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Ensure compliance with DORA’s ICT risk framework using runZero

Uncover the unmanaged and unknown to meet hidden risk requirements

With the Digital Operational Resilience Act (DORA) set to take effect on January 17th, 2025, financial institutions across the European Union must prepare to meet stringent regulatory requirements. At its core, DORA mandates resilience in Information and Communication Technology (ICT) systems, covering five primary pillars:

  1. ICT risk management

  2. Incident reporting

  3. Resilience testing

  4. Third-party risk management

  5. Information sharing

While these pillars seem straightforward, the implementation has a hidden complexity in meeting standards: unmanaged and unknown assets. These devices—ranging from decentralized IT assets to unconventional (but highly-interconnected ) IoT and OT devices—are notoriously hard to identify and secure.

Why are these unmanaged and unknown devices such a critical focus of DORA? The answer lies in their profound impact on the regulatory pillars. These assets, often hidden in the shadows of your environment, don’t just represent gaps in visibility—they create vulnerabilities that ripple through every aspect of operational resilience.

Consider this: over 60% of connected devices are invisible to defenders, and unmanaged assets were linked to 7 out of 10 breaches last year. To truly grasp the gravity of this problem, let’s explore how these blind spots hinder compliance across DORA’s relevant pillars—and what it takes to close those gaps effectively.

DORA chapter requirement

Downstream effect of unmanaged and unknown assets

ICT risk management

Develop and implement comprehensive frameworks to identify, assess, and mitigate information and communication technology (ICT) risks, ensuring robust protection against potential threats.

How can you protect something you don’t know exists? Unmanaged assets create gaps in your risk management framework, making it impossible to fully identify, assess, and mitigate vulnerabilities. Without a clear picture of your entire environment, staying compliant with DORA’s ICT risk management standards becomes a major challenge.

Incident reporting

Establish mechanisms for the timely detection and reporting of significant ICT-related incidents to regulatory authorities, facilitating prompt response and mitigation.

Unmanaged assets are often where problems start—and if they’re exploited, you might not even know an incident happened. That means delays in detection, reporting, and response, putting you at risk of missing DORA’s strict incident reporting timelines.

Resilience testing

Conduct regular testing of ICT systems to evaluate and enhance their resilience against disruptions, ensuring continuous and secure operations.

Resilience testing is about ensuring your ICT systems can handle disruptions. But if unknown assets aren’t included, you’re testing only part of your environment, leaving hidden risks unchecked. That’s a compliance issue waiting to happen.

Third-party risk management

Implement stringent oversight and management of third-party ICT service providers to ensure they adhere to security and resilience standards, thereby safeguarding the institution’s operations.

Shadow IT and forgotten vendor integrations often bring unmanaged assets into the mix. If you don’t have visibility into these, there’s no way to verify that your third-party providers are meeting DORA’s security and resilience standards.

To truly meet DORA’s requirements, you need complete visibility into your environment. Unmanaged and unknown assets are like puzzle pieces left out of the box; they make it impossible to see the full picture. Discovery and management of all your assets are the true foundation of compliance and resilience. Relying solely on traditional discovery and vulnerability management tools often leaves critical gaps, potentially putting you at risk of non-compliance—or worse, exposing your organization to security threats.

That’s where runZero comes in. Unlike traditional tools, runZero uncovers the unmanaged, unknown, and shadow IT assets that others miss using novel discovery and scanning techniques. In fact, enterprises on average find 25% more assets with runZero than they were previously aware of. Our objective is to provide you with unparalleled visibility across IT, OT, IoT, including those assets that aren’t actively managed. By layering in-depth fingerprinting data and detailed insights into vulnerabilities and exposures, runZero helps you to close those gaps, meet DORA’s requirements with confidence, and build a stronger, more resilient ICT environment.

DORA chapters

runZero alignment

ICT risk management

With runZero, you gain the tools to create and maintain robust ICT risk management frameworks. Complete asset discovery, continuous monitoring of IT, OT, IoT, and unmanaged devices, and identification of vulnerabilities and protection gaps across your critical operational assets ensure you have a complete view of your environment. This eliminates blind spots, supports thorough risk assessments, and empowers you to proactively mitigate ICT risks before they become problems.

Incident reporting

runZero provides detailed data on all assets, asset ownership, and associated exposures, helping you accurately assess the potential impact of incidents. You can easily map affected areas of the network and use runZero’s insights to classify and prioritize incidents effectively. With this level of clarity, you can respond rapidly to incidents, minimizing disruption and staying aligned with DORA’s reporting requirements.

Resilience testing

When it’s time to test your ICT systems’ resilience, runZero ensures your assessments cover the entire environment, both internally and externally. By providing visibility into system configurations, vulnerabilities, and sensitive areas, as well as leveraging external scanning to validate exposures on the edge, runZero helps you prioritize critical assets for testing. It maps out network structures and highlights exposures, so your testing efforts are targeted, accurate, and effective, ultimately strengthening your operational readiness.

Third-party risk management

If third-party ICT service providers are connected to your environment, runZero helps you keep them in check. It provides visibility into third-party managed assets, their network interactions, and any configuration changes that might introduce risks. With runZero, you can map dependencies, uncover vulnerabilities, and assess the impact of third-party services, enabling you to mitigate risks proactively and maintain a secure and resilient ICT ecosystem.

The high-level overview of how runZero aligns with DORA’s pillars demonstrates its powerful capabilities. However, to truly appreciate its impact, let’s explore how runZero directly maps to specific DORA articles, such as Articles 6, 7, 8, and 9. These articles outline the actionable steps required for ICT risk management, resilience, and collaboration. The section below also illustrates how runZero goes beyond compliance to deliver operational excellence.


 

Article 6: ICT risk management framework

What DORA requires:

  • Develop a framework to identify, assess, and mitigate ICT risks.

  • Address risks tied to internal systems, third-party services, and external threats.

 

Key challenges:

  • ICT risk management frameworks often rely on incomplete inventories.

  • Without identification of all assets and understanding device interdependencies, assessing impact and mitigation strategies is guesswork.

 

How runZero helps:

runZero supports the creation and maintenance of ICT risk management frameworks by delivering advanced asset discovery, continuous monitoring of IT, OT, IoT, and unmanaged devices, and identifying vulnerabilities and security control gaps.

  1. Complete asset discovery:
    • Identifies all IT, OT, IoT, and unmanaged devices using active scanning, passive scanning, and integrations.

    • Incorporates external scanning to identify assets and monitor risks on the edge, ensuring comprehensive visibility across both internal and external attack surfaces.

    • Accurately and precisely fingerprints assets providing deeper insights for more accurate risk assessment and mitigations.

    • Detects shadow IT and rogue devices not visible to traditional tools.

  2. Risk interdependency mapping:
    • Maps relationships between assets, revealing critical dependencies.

    • Identifies single points of failure, such as connections between essential systems and vulnerable third-party services.

  3. Risk monitoring:
    • Identifies issues beyond CVEs, such as misconfigurations, segmentation weaknesses, insecure services, EoL, policy violations, etc.

    • Monitors for emerging risks and zero-day vulnerabilities through the Rapid Response Program, enabling swift identification of vulnerable assets without the need for rescanning.

    • Tracks changes in device configurations and interdependencies.

    • Uses safe scanning to identify fragile devices without the risk of disrupting operations.

    • Alerts on deviations, such as newly connected devices or unexpected configuration changes, that introduce new risks.

  4. Enriched risk context:
    • Integrates with a broad range of existing security solutions in your stack to provide enriched asset data, improving risk analysis and prioritization.

Outcome:
runZero ensures that your ICT risk management framework is underpinned by a complete and up-to-date view of all assets, enabling precise risk assessment, mitigation, and operational resilience.


 

Article 7: ICT systems, protocols, and tools

What DORA requires:

  • Implement secure ICT systems and tools designed to safeguard the organization’s digital infrastructure from unauthorized access and cyber threats.

  • Maintain a complete and continuously updated inventory of ICT assets.

  • Conduct regular resilience testing through vulnerability assessments and security audits.

 

Key challenges:

  • Legacy discovery tools fail to capture non-traditional protocols or devices outside standard IT ecosystems.

  • Inventory updates are often manual, leading to outdated or incomplete data.

  • Testing often overlooks unmanaged or obscure devices, leaving blind spots.

 

How runZero helps:

With runZero, you gain visibility into your IT, OT, and IoT assets, ensuring every device in your environment is tracked and accounted for. This gives you the deep insight needed to uncover vulnerabilities, misconfigurations, and insecure protocols while mapping interdependencies to reveal hidden security gaps. By spotlighting all assets and exposures, runZero helps you ensure nothing is overlooked, empowering you to make more accurate assessments and build stronger defenses.

  1. Complete, up-to-date inventory management:
    • Provides comprehensive visibility into both internal and external assets, including IT, OT, and IoT devices to ensure all systems are tracked.

    • Regularly updates asset data through continuous monitoring, maintaining up-to-date visibility into the network’s infrastructure.

    • Discovers unknown and unmanaged devices that may not have been previously tracked, ensuring that all assets are accounted for.

    • Updates inventories continuously through automated scanning, ensuring accuracy.

  2. Informs security of ICT systems, protocols, and tools:
    • Identifies CVEs and non-traditional vulnerabilities, such as insecure services and segmentation weaknesses, that compromise infrastructure.

    • Continuously monitors for new or unexpected devices, ensuring prompt response to unauthorized access attempts.

    • Detects outdated or misconfigured protocols like SMBv1, Telnet, or unencrypted HTTP.

    • Maps interdependencies between systems, helping organizations understand how internal and external assets interact including gaps or deficiencies in security controls and segmentation weaknesses

  3. Resilience testing optimization:
    • Ensures that all assets, including hidden and rogue devices, are included in vulnerability assessments and threat-based testing procedures.

    • Supports more accurate threat assessments by continuously updating data on internal and external attack surfaces, even as they change.

    • Provides detailed context for each device, such as OS versions, open ports, and known vulnerabilities (CVEs), to prioritize testing efforts.

  4. Third-party tool integration:
    • Integrates with vulnerability management and endpoint security tools to enhance testing scopes and ensure no assets are missed.

Outcome
runZero delivers detailed asset visibility, empowering your teams to secure ICT systems and conduct comprehensive resilience testing with confidence.


 

Article 8: Identification of critical assets

What DORA requires:

  • Identify and prioritize critical ICT assets and services.

  • Map interdependencies between systems to understand potential cascading failures.

  • Continuously monitor critical assets for emerging risks.

 

Key challenges:

  • Identifying critical assets isn’t just about visibility; it requires understanding each device’s function, connectivity, and risk profile.

  • Interdependency mapping is complex, particularly when third-party services or legacy systems are involved.

  • Monitoring is often siloed, missing broader network impacts.

 

How runZero helps:

runZero gives you full visibility into your critical IT, OT, and IoT assets, maps out how they’re connected, and spots risks like vulnerabilities or misconfigurations. By continuously keeping an eye on everything, it helps you stay ahead of threats and keep your most important systems secure.

  1. Critical asset discovery:
    • Identifies critical devices and services through advanced fingerprinting techniques.

    • Highlights assets critical to business operations based on their roles and interdependencies.

  2. Comprehensive risk mapping:
    • Maps interdependencies across IT, OT, IoT, and third-party systems.

    • Visualizes network connections and highlights cascading risks from single points of failure.

    • Combines detailed internal fingerprinting with external data sources to uncover hidden risks such as shared cryptographic keys, cloned assets, and overlooked misconfigurations that EASM tools miss.

    • Highlights network segmentation issues.

  3. Risk prioritization:
    • Assesses vulnerabilities in critical systems, including software versions, configuration issues, and exposure levels.

    • Monitors for emerging risks and zero-day vulnerabilities through the Rapid Response Program, enabling swift identification of vulnerable assets and timely remediation.

    • Assesses and prioritizes externally facing assets as critical, highlighting high-risk targets with vulnerabilities or misconfigurations that could expose the organization to external threats.

    • Flags critical assets with high-risk vulnerabilities or misconfigurations.

  4. Continuous monitoring:
    • Tracks changes in critical systems, such as new software vulnerabilities or configuration deviations.

    • Monitors for emerging threats, such as exploits targeting specific device types.

Outcome:
runZero provides a detailed, dynamic understanding of critical assets, their risks, and their interdependencies, enabling your team to make more informed decision-making and proactive risk mitigation.


 

Article 9: Protection & prevention

What DORA requires:

  • Regularly update software and apply security patches.

  • Address vulnerabilities promptly to minimize risks across systems.

 

Key challenges:

  • Legacy systems and IoT devices often have unique patching challenges, such as vendor-specific firmware updates.

  • Traditional vulnerability management tools struggle to identify end-of-life (EOL) systems or devices with no official CVEs.

 

How runZero helps:

With runZero, you get actionable insights to identify vulnerabilities, enforce security policies, monitor patch status, and stay ahead of emerging risks—ensuring your protection and prevention measures, from IT to IoT, are secure and compliant.

  1. Vulnerability identification:
    • Monitors for emerging risks and zero-day vulnerabilities through the Rapid Response Program, enabling swift identification of vulnerable assets without the need for rescanning.

    • Detects outdated software and unpatched systems across all device types, including OT and IoT.

    • Highlights vulnerabilities in non-traditional assets, such as smart cameras or building management systems.

  2. Policy enforcement:
    • Flags misconfigurations, insecure protocols, and policy violations on a continuous basis.

    • Identifies segmentation weaknesses that expose critical systems to lateral movement attacks.

  3. Patch monitoring:
    • Tracks patch status for all devices, ensuring critical systems are prioritized.

    • Identifies EOL systems, providing actionable recommendations for replacements or compensating controls.

  4. Time-sensitive risk updates:
    • Monitors the external attack surface for vulnerabilities in known or unknown assets exposed on the network edge, ensuring timely detection and mitigation of risks.

    • Continuously monitors for new vulnerabilities or exploits targeting devices in your environment.

    • Alerts on deviations from secure configurations, such as weakened encryption protocols.

Outcome:
runZero empowers your team to proactively manage patching and configuration efforts, ensuring no vulnerabilities are left unchecked—even in unconventional or legacy systems.


 

runZero: Your Partner in DORA Compliance

Compliance with DORA is a monumental challenge that requires comprehensive asset visibility and continuous exposure management. runZero’s capabilities go beyond traditional solutions, offering financial institutions a unified solution to:

  • Discover all assets, including IT, OT, IoT, and unmanaged devices.

  • Monitor continuously for new vulnerabilities, changes, and risks across your completed attack surface..

  • Provide detailed data to enrich security and compliance workflows.

With runZero, you can bridge the gaps that traditional tools leave behind, ensuring not just compliance, but true resilience against today’s evolving cyber threats.

 

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

How to find VMware vCenter assets on your network

Latest vCenter vulnerabilities

Broadcom has issued a security advisory for VMware vCenter that indicates that one of the two vulnerabilities disclosed on the 17th of September, 2024,  CVE-2024-38812, which was fully patched by October 21, is under active exploitation in the wild.

This vulnerability has a CVSS score of 9.8, which is considered highly critical.

What is the impact?

An attacker with remote access to a vulnerable system could send specially crafted requests that could trigger a heap-overflow and result in remote code execution or privilege escalation into root.

Are updates or workarounds available?

Broadcom has issued patches to resolve both vulnerabilities. Reference the Response Matrix section of the advisory for the appropriate fixed version to apply in your environment.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

product:vCenter

 


CVE-2024-38812 and CVE-2024-33813 (September 2024)

Broadcom has issued a security advisory for two vulnerabilities that affect VMware vCenter, which exists in both VMware vSphere and VMware Cloud Foundation products.

  • CVE-2024-38812 is rated critical with CVSS score of 9.8, and potentially allows for remote code execution.
  • CVE-2024-38813 is rated high with CVSS score of 7.5, which can result in privilege escalation into root.

What is the impact?

An attacker with remote access to a vulnerable system could send specially crafted requests that could trigger a heap-overflow and result in remote code execution or privilege escalation into root.

Are updates or workarounds available?

Broadcom has issued patches to resolve both vulnerabilities. Reference the Response Matrix section of the advisory for the appropriate fixed version to apply in your environment.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

product:vCenter

 

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

How to find Fortinet assets on your network

Latest Fortinet vulnerabilities

Fortinet has issued advisories for its FortiAnalyzer, FortiAnalyzer-BigData, FortiManager, and FortiOS products.

  • CVE-2023-50176 detailed in FG-IR-23-475 is rated high with a CVSS score of 7.1, and may allow an unauthenticated attacker to hijack a user session.
  • CVE-2024-23666 detailed in FG-IR-23-396 is rated high with a CVSS score of 7.1 and may allow an authenticated, read-only user the ability to execute “sensitive operations”.

What is the impact?

CVE-2024-23666, which affects FortiAnalyzer and FortiManager products, requires that an attacker (or malicious user) is authenticated against the system. A read-only user can potentially execute sensitive operations through crafted requests, bypassing client-side enforcement through the web interface. CVE-2023-50176, which affects the SSLVPN component of FortiOS, is a session fixation vulnerability that allows an unauthenticated attacker the ability to hijack an authenticated user’s session via a “phishing SAML authentication link”.

Are updates or workarounds available?

The vendor has released patches for all affected products. They recommend following the upgrade path using their upgrade tool.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

hw:FortiManager OR hw:FortiAnalyzer OR os:FortiOS

March 2024

On March 12th, 2024, Fortinet disclosed several vulnerabilities in their FortiOS, FortiProxy, and FortiClient products:

  • FG-IR-23-328 – a buffer overflow vulnerability in the handling of form-based authentication in the FortiOS and FortiProxy captive portals, allowing remote, unauthenticated attackers to execute arbitrary code. This vulnerability has been assigned CVEs CVE-2023-42789 and CVE-2023-42790. These vulnerabilities have a CVSS score of 9.3, indicating that they are critical.

  • FG-IR-24-007 – a SQL injection vulnerability in the FortiClient Enterprise Management Server. This vulnerability has been designated CVE-2023-48788, and has been given a CVSS score of 9.8 (critical).

  • FG-IR-23-390 – a log injection vulnerability in the FortiClient Enterprise Management Server. This vulnerability has been assigned CVE-2023-47534 and a CVSS score of 7.7 (high).

  • FG-IR-23-103 – a remote code execution vulnerability in the FortiManager product. This vulnerability has been designated CVE-2023-36554 with a CVSS score of 7.7 (high). Note that the vulnerable subsystem is not installed by default.

  • FG-IR-23-013 – an information disclosure vulnerability in the FortiGuard SSL-VPN product. This vulnerability has been designated CVE-2024-23112 and given a CVSS score of 7.2 (high).

Upon successful exploitation of these vulnerabilities, attackers could execute arbitrary code on the vulnerable system or disclose privileged information. Fortinet released updates to mitigate this issue and all users were urged to update immediately.

How to find FortiOS, FortiProxy or FortiClient operating systems

From the Asset Inventory, use the following query to locate assets running the FortiOS or FortiProxy operating systems, which may be vulnerable:

os:"FortiOS" OR os:"FortiProxy"

Additionally, from the Services Inventory, use the following query to locate potentially vulnerable systems:

html.title:="FortiClient Endpoint Management Server"

CVE-2024-21762 (February 2024)

On February 8th, 2024, Fortinet disclosed a serious vulnerability in their FortiOS operating system, used by multiple Fortinet products.

The issue, CVE-2024-21762, allowed attackers to execute arbitrary code on vulnerable devices. The vendor has indicated that this is a critical vulnerability. The vendor reports that there are indications that this vulnerability may be actively exploited in the wild. Upon successful exploitation of these vulnerabilities, attackers could execute arbitrary code on the vulnerable system.

Fortinet released an update to mitigate this issue and all users were urged to update immediately. Additionally, the vendor indicated that disabling the SSL-VPN functionality of the device would mitigate the issue.

How to find FortiOS devices

From the Asset Inventory, use the following query to locate assets running the FortiOS operating system which may potentially be vulnerable:

os:"FortiOS" AND tcp:443

CVE-2022-40684 (October 2022)

News surfaced in October 2022 of a critical authentication bypass vulnerability present in the web administration interface of some Fortinet products. Successful exploitation of this vulnerability (tracked as CVE-2022-40684) via crafted HTTP and HTTPS requests could provide remote attackers with admin-level command execution on vulnerable FortiOS devices including FortiGate firewalls, FortiProxy web proxies, and FortiSwitchManager assets.

With a CVSS critical score of 9.6, attackers running admin-level commands on compromised assets may have had the ability to persist presence, explore connected internal networks, and exfiltrate data. At the time Fortinet was aware of at least one exploit of this vulnerability in the wild, and Bleeping Computer offered a Shodan search showing more than 140k publicly accessible FortiGate devices potentially running vulnerable FortiOS. Additionally, security researchers with Horizon3.ai planned on publishing an exploit PoC. For admins wanting to check if a FortiOS/FortiProxy/FortiSwitchManager asset had been exploited, Fortinet provides an indicator of compromise (see the “Exploitation Status” section).

Fortinet called out the vulnerable FortiOS, FortiProxy, and FortiSwitchManager versions in their advisory and had made updates available for affected products. Admins were advised to ensure that affected models were updated to the latest version as soon as possible. If updates could not be completed in the near term, Fortinet provided some mitigation steps (see the “Workaround” section) that could be taken to secure vulnerable assets.

How to find FortiOS, FortiProxy, and FortiSwitchManager assets

From the Asset Inventory, runZero users entered the following pre-built query to locate FortiOS, FortiProxy, and FortiSwitchManager assets:

os:FortiOS or product:FortiProxy or product:FortiSwitchManager

 

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

How to find FortiManager instances on your network

Latest FortiManager vulnerability 

Fortinet has issued an advisory for its Fortinet FortiManager product. The vendor confirms that this vulnerability is being actively exploited in the wild.

This vulnerability has been designated CVE-2024-47575 and has been assigned a CVSS score of 9.8 (extremely critical).

Note that this vulnerability is the same one discussed in an earlier version of this blog post, prior to vendor confirmation.

What is the impact?

The vulnerability would allow remote code execution by an attacker with upon connection to a FortiManager instance. Attackers need to have a valid Fortinet device certificate, but this certificate can be obtained from an existing Fortinet device and reused.

Successful exploitation of this attack is reported to allow remote code execution, potentially leading to total compromise of the vulnerable system.

The vendor has released a list of indicators of compromise (IOCs); users are encouraged to use this list to determine if a system has been successfully attacked.

Are updates or workarounds available?

The vendor has released updates and mitigation strategies to address this issue, and the vendor advises users to update as quickly as possible. Mitigation strategies include disabling the affected service and denying registration to systems with unknown serial numbers.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

hw:FortiManager

 

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

How to find SolarWinds Web Help Desk services on your network

Latest SolarWinds vulnerability (CVE-2024-28987)

According to the US Cybersecurity and Infrastructure Security Agency (CISA), a critical hardcoded password vulnerability within SolarWinds’ Web Help Desk software is actively being exploited and was added to their Known Exploited Vulnerability (KEV) catalog.

  • CVE-2024-28987 is rated critical with CVSS score of 9.1 allowing for unauthorized access by a remote attacker.

What is the impact?

A remote attacker has the ability to log in to a vulnerable system using hardcoded credentials, providing access to internal information with the ability to modify the data.

Are updates or workarounds available?

According to the security advisory issued by SolarWinds, systems running “WHD 12.8.3 HF1 and all previous versions” of the Web Help Desk software are affected. Organizations are recommended to manually apply the hot fix released by SolarWinds to remove the hardcoded credentials from the software.

How to find potentially vulnerable systems with runZero

From the Service Inventory, use the following query to locate systems running potentially vulnerable software:

_service.product:="SolarWinds:Web Help Desk:"
 

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

How to find Palo Alto Network firewalls running PAN-OS

Latest Palo Alto Networks vulnerabilities

Palo Alto Networks (PAN) released a security advisory with multiple vulnerabilities on PAN-OS firewalls that could lead to admin account takeover.

  • CVE-2024-9463 is rated critical with CVSS score of 9.9, is an OS command injection vulnerability and potentially allows for  and execution of OS commands as root.
  • CVE-2024-9464 is rated critical with CVSS score of 9.3, is an OS command injection vulnerability and potentially allows for the execution of OS commands as root.
  • CVE-2024-9465 is rated critical with CVSS score of 9.2, is a SQL injection vulnerability and potentially allows a remote unauthenticated attacker to read the contents of the Expedition database.
  • CVE-2024-9466 is rated high with CVSS score of 8.2, and potentially allows for an authenticated user to read sensitive information including passwords and API keys.
  • CVE-2024-9467 is rated high with CVSS score of 7.0, is an XSS vulnerability and potentially allows for execution of malicious JavaScript code that could result in session hijacking.

What is the impact?

If chained together through an exploit, a firewall running the vulnerable software could be completely taken over by an unauthenticated remote attacker. For more information, the team that disclosed the vulnerabilities to Palo Alto Networks, published a detailed analysis.

According to the vendor, there is no known malicious exploitation of vulnerable systems at this time.

Are updates or workarounds available?

According to Palo Alto Networks, “The fixes for all listed issues are available in Expedition 1.2.96, and all later Expedition versions.” They also recommended rotating all passwords and API keys after applying the latest patch to prevent future unauthorized access. Refer to the Workarounds and Mitigations section of the security advisory for information about potential workarounds and additional advice.

How to find potentially vulnerable PAN-OS systems with runZero

From the Asset Inventory you can use the following query to locate potentially vulnerable systems:

os:"PAN-OS"

CVE-2024-3400

Palo Alto Networks (PAN) disclosed that certain versions of their PAN-OS software has a vulnerability that allows for remote command injection.

CVE-2024-3400 is rated critical with CVSS score of 9.8 and indicates an unauthenticated attacker can execute arbitrary code with root privileges on the firewall. The vendor indicates that there is evidence of limited exploitation in the wild.

watchTowr has posted a detailed analysis including the details needed for exploitation. This analysis covers two separate vulnerabilities; an arbitrary file creation vulnerability in the session handler, and a shell metacharacter injection issue that leads to remote execution through the telemetry script. PAN has updated their guidance to state that “Disabling device telemetry is no longer an effective mitigation“.

What is the impact?

The following PAN-OS versions are affected by this vulnerability.

Version

Affected

Unaffected

PAN-OS 11.1

< 11.1.2-h3

>= 11.1.2-h3 (hotfix ETA: By 4/14)

PAN-OS 11.0

< 11.0.4-h1

>= 11.0.4-h1 (hotfix ETA: By 4/14)

PAN-OS 10.2

< 10.2.9-h1

>= 10.2.9-h1 (hotfix ETA: By 4/14)

Palo Alto Networks indicates that PAN-OS 11.1, 11.0, and 10.2 versions with the configurations for both GlobalProtect gateway and device telemetry enabled.

Customers may verify this by checking for entries in the firewall web interface (Network > GlobalProtect > Gateways) and verify whether device telemetry enabled by checking your firewall web interface (Device > Setup > Telemetry).

Are updates or workarounds available?

Palo Alto Networks recommends that customers with a Threat Prevention subscription can block attacks for this vulnerability by enabling Threat ID 95187 (introduced in Applications and Threats content version 8833-8682) and applying vulnerability protection to GlobalProtect interfaces.

It is also recommended that telemetry be disabled until devices can be upgraded to an unaffected version of PAN-OS.

How runZero users found potentially vulnerable PAN-OS systems

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

os:"PAN-OS"

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

RDP security: The impact of secure defaults and legacy protocols

Microsoft’s Remote Desktop Services (RDS) is a commonly used technology for providing a remote Windows graphical environment. RDS use cases range from merely enabling remote server management all the way to providing full Virtual Desktop Infrastructure (VDI) for enterprises. In this blog, we’ll explore how the network level security controls have evolved to address risks, the reasons why defaults can impact an environment’s security, and using runZero to audit your environment.

In the beginning (abridged) 

In 1995, before RDS, Citrix released a multi-user remote desktop product called WinFrame, based on Windows NT 3.51. This was promising enough that Microsoft later licensed the core technology from Citrix and used it to build a product called Terminal Services. It was first released in 1998 as Windows NT 4.0 Terminal Server Edition. In Windows 2000, Terminal Services became a standard Windows feature. After that, nearly every version of Windows Server improved on RDS in some way.

The network protocol used for communication between the RDS client and server is called Remote Desktop Protocol (RDP). The protocol evolved alongside the RDS changes and was the impetus for various improvements. Many of the security controls discussed in this blog are changes to RDP.

Not remotely secure

It will likely surprise no one that a protocol and corresponding implementations from the 1990s and early 2000s had security problems. The impact of these problems grew over time as more organizations started exposing the RDS services directly on the Internet. Some organizations were doing this to enable remote management of servers while others were hosting applications and other services for clients.

The major issues that we’re going to cover here are:

Information disclosure

When a client connected to RDS they would be presented a login screen. By default, the login screen often displayed a list of recent users and Windows Domain or Active Directory that the server was part of. This information could then be used in brute force attacks.

FIGURE 1 – Legacy RDS pre-login screen

Brute force attacks

The client side of the RDP protocol required minimal resources and there were no controls in place to stop attackers from using tools such as Hydra or Ncrack to test various username and password combinations in order to discover valid credentials. While Administrators could configure Windows policies to lock out accounts after a certain number of failed login attempts this precaution often wasn’t enforced for Administrator accounts – admins always had login access.

Denial of service

During the initial client connection and prior to authentication, the server provisioned an entire desktop environment before beginning the login process. This meant that attackers could easily create a resource-exhaustion situation by simply opening a large number of sessions. This could happen accidentally as part of an effort to brute force credentials.

Machine-in-the-Middle

The early versions of RDP were susceptible to Machine-in-the-Middle (MitM) attacks that could enable decryption or modification of RDS session data. They used a form of authentication that is now known to have many weaknesses. The encryption used was a stream cipher named RC4. At the time RC4 was commonly used in various protocols such as WEP, WPA, SSL, and TLS. Today, however, it is known to be broken by multiple techniques and the key sizes are such that modern computers make short work of them. It became so risky that RFC 7465 was drafted in 2015 to prohibit RC4’s use in all TLS versions. Further compounding the RDS risks, RDP allowed keys sizes as small as 40 bits in order to comply with US cryptographic export restrictions.

The issues with authentication didn’t end there. Microsoft’s implementation of the key exchange protocol depended on the client and server creating and exchanging random values. The server’s random value was sent unencrypted over the network. The server also provided a public RSA key that could be used by the client to encrypt the client’s random value so that only the server could read it. Unfortunately, Microsoft baked the same public-private RSA key pair into every RDS host. This key was, predictably, extracted and made public. With that information attackers with network access to RDS communications could decrypt the data and extract authentication and session information. Advanced attackers in the correct network position could intercept and monitor or modify an RDS session in real time.

Shoring up defenses

With the release of Windows 2003 Service Pack 1, Microsoft introduced the ability to use TLS, which addressed the issue of machine-in-the-middle (MitM) attacks by enabling the use of significantly more robust encryption cipher suites and key exchange protocols. This also enabled the protocol to take advantage of improvements in TLS over time instead of being locked into a single algorithm. Additionally, TLS allows clients to cryptographically verify they were connecting to the expected server.

In Windows Server 2008, Microsoft introduced Network Level Authentication (NLA), which required users to authenticate themselves before a session would be established. NLA forced authentication to occur after the TLS handshake, but before the console was provisioned, which mitigated the resource-exhaustion concerns, reduced information leakage, and significantly impaired brute-force attacks. Since information leakage was reduced attackers could no longer collect the names of users, but they could still access the Windows hostname and domain information via the CredSSP authentication process. However, this is still an overall improvement in security. There is one downside to requiring NLA – users can no longer authenticate and change expired passwords. This functionality has to be provided via another mechanism such as a Remote Desktop Gateway.

When configuring RDS in Windows Server 2008, administrators had the option to require NLA for all connections or to allow the client to decide. Starting with Windows Server 2012, however, NLA was required by default to improve security across Windows environments.

Real world impact of NLA by default

We explored our data to determine if requiring NLA by default had a real world impact. In other words, do we see a significant percentage of assets where a less secure option has been enabled for Window Server 2012 and beyond?

The chart below shows the overall percentage of specific Windows operating systems (OS) in our data as well as the breakdown of NLA is enforcement.

FIGURE 2 – Operating system distribution for RDP NLA enforcement.

As the results illustrate, the majority of RDS on Windows Server versions where NLA is required by default do, in fact, require NLA. This is great news. It indicates that secure defaults can have a positive impact on security posture. Another takeaway is that more modern environments are less likely to operational or compatibility requirements that force less secure configurations. An argument could be made that the NLA requirement being disabled by default on Windows Server 2008 / 2008 R2 shows up in the results as well, but this state may be influenced by those servers being more likely to have legacy or third-party clients that don’t support NLA.

We also reviewed the OS distribution of services that did not permit using NLA at all. This list is dominated by Red Hat Enterprise Linux and its various derivatives running the xrdp RDP service. The xrdp service does not currently support NLA, so these results are not surprising. However, we were encouraged to find so few results for Microsoft Windows machines without NLA support that the number is not statistically significant.

FIGURE 3 – Operating system distribution for RDP without NLA support.

Using runZero to audit RDP configurations

At runZero we put a tremendous amount of effort into trying to extract as much information from scan targets as possible, particularly if the information can help us understand the security posture of the device. From RDS services this includes enumerating all of the RDP authentication mechanisms that target supports. Explore our recommendations to audit RDP configurations in your environment.

Attributes of interest

We store RDP authentication attributes on the RDP service of an asset with the prefix rdp.auth. Here are the attributes that can be used to audit your environment to check to see if NLA is enabled or required as well as if standard, legacy RDP authentication is still enabled:

  • rdp.auth.nla – a value of supported indicates that the target supports NLA (this is good!).

  • rdp.auth.rdp – a value of supported indicates that the target still allows authentication using the legacy RDP mechanism. (Red flag. It should only really be required if you have very old clients that still need to connect).

  • rdp.auth.ssl – a value of supported indicates that the target still allows authentication using the TLS. (Somewhere in the middle. This is better than legacy RDP but still weaker than NLA).

In rdp.auth.rdp and rdp.auth.ssl a value of ERROR_HYBRID_REQUIRED_BY_SERVER indicates that the authentication mechanism is not supported and NLA is required. This is the desired state.

Within runZero you can use a Service inventory search to audit your environment. To find assets supporting legacy RDP authentication you can use the following search criteria:

protocol:rdp and _service.rdp.auth.rdp:="supported"

To find assets supporting either legacy RDP or SSL the following Service inventory search criteria can be used:

protocol:rdp and (_service.rdp.auth.rdp:="supported" OR _service.rdp.auth.ssl:="supported")

A glance into the near future

An interesting recent development is the introduction of Remote Desktop (using the RDP protocol) to both the Gnome and KDE desktop environments. In both cases Remote Desktop is a full fledged, native feature. Based on the currently released code, it appears that the implementations support NLA and do not support either the legacy RDP or SSL protocols. We will be monitoring the growth of these implementations over time and look forward to sharing more insight on that in the future.

Final Thoughts

Thankfully, the security of Microsoft’s RDS has improved over time. As with many such improvements, the benefits are lost if the new features are not implemented. In this case, Microsoft made the pragmatic decision for the most secure option to also be the default and we can measure the real world impact. In short, secure-by-default matters.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

How to find D-Link routers on your network

D-Link released a Security Announcement regarding vulnerabilities found within two of their DIR-X WiFi 6 routers (DIR-X5460 – AX5400, DIR-X4860 – EXO AX AX4800) and one of their non-US Mesh routers (COVRX1870 – AX1800).

  • CVE-2024-45694 is rated critical, with CVSS score of 9.8, and allows for an unauthenticated attacker to potentially execute arbitrary code.

  • CVE-2024-45695 is rated critical, with CVSS score of 9.8, and allows for an unauthenticated attacker to potentially execute arbitrary code.

  • CVE-2024-45696 is rated high, with CVSS score of 8.8, and allows for unauthorized access by an attacker.

  • CVE-2024-45697 is rated high, with CVSS score of 9.8, and allows for unauthorized access to the system by an attacker and the ability to execute arbitrary commands.

  • CVE-2024-45698 is rated high, with CVSS score of 8.8, and allows for unauthorized access to the operating system by an attacker and the ability to execute arbitrary commands.

What is the impact?

Successful exploitation of the critical vulnerabilities through a stack overflow allows attackers to perform remote code execution (RCE) by sending malicious requests to vulnerable devices. The high severity vulnerabilities affect the target device’s telnet service. CVE-2024-45696 allows for an attacker to forcibly enable telnet on the device, but must be on the same network as the device to log in through the telnet service. CVE-2024-45696, CVE-2024-45697, and CVE-2024-45698 allow for an attacker to log in to the telnet service using hard-coded credentials, if the service is enabled.

Are updates or workarounds available?

D-Link has issued patches for each of the affected devices available for download in the Affected Models section of the announcement.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

mac_vendor:"D-Link"

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

How to find SonicWall devices on your network

Latest SonicWall vulnerability: (CVE-2024-40766) 

SonicWall disclosed a vulnerability that affects SonicOS management access and SSLVPN software on SonicWall Gen 5, Gen 6, in addition to Gen 7 devices running SonicOS version 7.0.1-5035 or earlier.

CVE-2024-40766 is rated critical with CVSS score of 9.3, and potentially allows for unauthorized resource access by an attacker. There is limited evidence that this vulnerability is being exploited in the wild.

What is the impact?

Successful exploitation of this vulnerability potentially results in unauthorized resource access and in some cases could lead to a DoS after causing vulnerable devices to crash.

Are updates or workarounds available?

SonicWall recommends restricting management access to trusted sources or disabling WAN management from the public Internet. Additionally, SonicWall has released updated firmware and is available for download from mysonicwall.com.

How to find potentially vulnerable systems with runZero

From the Asset Inventory, use the following query to locate systems running potentially vulnerable software:

hw:"SonicWall" type:"Firewall"

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.

Proven fingerprinting techniques for effective CAASM

One of the key components of runZero’s ability to provide asset discovery, exposure management, and attack surface management data is its ability to identify an asset’s operating system (OS), hardware, and services aka fingerprinting. This is often performed with very little or even conflicting data.

In this blog, we explore commonly used fingerprinting techniques and gain insights from the runZero Research Team on their approach to deciphering a real-world fingerprinting challenge. Let’s go!

Fingerprinting concepts

For the purposes of this blog, “fingerprinting” is defined as the process of trying to identify, with as much precision as possible, some aspect of an asset. There can be significant variation in the precision that can be achieved when fingerprinting. With certain data we may be able to identify the operating system and exact build number. With different data, it may only be possible to vaguely bucket the asset into an OS family such as “Windows” or “Linux.” For services we can sometimes even determine the programming language it was written in and perhaps a range of language versions that may have been used. All outcomes can be possible against the same asset depending on which protocols and services we can observe.

Fingerprinting techniques generally fall into one of three categories:

An example of self identification based fingerprinting would be an SSH MOTD banner of “Red Hat Enterprise Linux Server release 5.11 (Tikanga)”. That is pretty straightforward and doesn’t require any additional data. Attribute based fingerprinting, which we will discuss further in the next sections, includes looking at various response and data attributes such as TCP field values such as MSS or Window Scale. Behavior based techniques typically take more work to find and implement. An example would be when a particular OS or service implementation drops a TCP connection only when sent a certain payload at a particular stage in protocol negotiation.

A hat by any other name #

Identifying the OS of a network-connected system, without credentials, and with minimal services, has always been a game of precision. Some of the trickiest examples are the forks of the Red Hat Enterprise Linux (RHEL) distribution.

CentOS and certain other Linux distributions such as Oracle Linux were originally forks or “bug and binary compatible” redistributions of Red Hat Enterprise Linux. The relationship changed in 2021 when Red Hat, which acquired CentOS in 2014, discontinued CentOS Linux and created CentOS Stream. With this change CentOS would no longer be downstream of RHEL but would instead be the upstream source from which RHEL is created. The logical flow has since changed again and now has Fedora as the root with both CentOS Stream and RHEL downstream. In response to CentOS Linux being discontinued two new distributions were created: AlmaLinux OS and Rocky Linux.

Often, the only real difference between these distributions is the replacement of Red Hat trademarks and branding with that of the particular Linux project. In many cases, these distributions are byte-for-byte identical at the software package and network levels. These present a challenge to remote fingerprinting as a result.

To overcome these challenges, we collect and analyze enormous amounts of data. Our first pass at trying to differentiate the RHEL derivatives used a combination of two attributes, such as SSH version negotiation strings and the TCP Receive Window size. Over time, we realized this wasn’t going to be sufficient and that we needed more and better data.

Analyzing data at scale is useful, but in situations like this it is vital to know exactly what combination of distribution and version leads to what results. For this effort we built hundreds of virtual machines running as many versions of the different distributions as we could. In some cases, these releases were over two decades old!

Verify target, one SYN only #

From each of these virtual machines we collected as much information as we could about how the TCP stack communicated. While it is true that fingerprinting an operating system via TCP stack quirks has been a thing for years, our challenge was to improve our detection while sending the absolute minimum amount of traffic and, importantly, to look for evidence that would persist through common configuration changes by the system administrators.

To explain our findings, we first need to define some terms:

  • TCP Receive Window: Maximum amount of data that a particular endpoint can receive and buffer. The sending host has to stop after sending the maximum amount of data and wait for ACK and window updates.

  • MTU: Maximum Transmission Unit, which is the largest packet that the network interface can accept.

  • MSS: Maximum Segment Size, which is the maximum amount of TCP data that can fit into a single packet, calculated as the MTU minus the protocol headers.

  • TCP Window Scale: An optional factor by which the TCP Receive Window is scaled; this allows receive windows to exceed the maximum of 65535 bytes that can be specified in the TCP Receive Window field.

Of the TCP attributes that we observed, the one that provided the murkiest fingerprinting results was the TCP Window Scale. The values for it, when present, range from 0 to 14. With this information, we can usually determine if the target is running a general family of operating systems.

 

FIGURE 1 – TCP Window Scale by operating system.

Combining the TCP Receive Window and MSS offered the next significant improvement. In our past work, leveraging the Receive Window size sometimes yielded values that seemed to change unexpectedly. The reason why became clear when we looked at the data from the lab.

The key points were:

  • Changes to the link-layer MTU impacts the value of MSS, since MSS is calculated as the MTU minus the size of certain TCP/IP headers.

  • MSS is different between IPv6 and IPv4 due to the IPv6 IP headers being 20 bytes larger.

  • For Linux-based systems, Receive Windows less than the maximum value were almost always an even multiple of MSS. Due to the MSS difference mentioned above this means that the Receive Windows would vary as well.

  • Critically, the MSS multiplier for Linux-based OSs correlated with the Linux kernel version.

With the information above in hand, we can organize Linux systems into specific kernel version buckets based on the observed multiplier. That is quite a bit of information from the response to a single SYN packet!

FIGURE 2 – Relationship between IPv4/IPv6 MSS Multiplier and Linux Kernel version.

The kernel version also offers a hint as to the relative age of the system. A MSS multiplier of 4 indicates that the machine is likely running an ancient version of Linux, far beyond EOL, and certainly not something that should still be in production.

A little from column A, a little from column B #

TCP-based fingerprinting by itself doesn’t improve fingerprinting of RHEL derivatives as much as we’d like. Since most of the systems in our analysis had SSH running, we looked for patterns in RHEL-derivative type and version in the light of SSH version negotiation advertisements (for example, SSH-2.0-OpenSSH_8.7) combined with the Linux kernel version. This strategy quickly yielded results. We found that we could generally identify the distribution’s major version, and in some cases, minor version range as well.

The screenshots below demonstrate how specific patterns pop out under bulk analysis.


FIGURE 3 – Relationship between different Enterprise Linux distribution versions and various network attributes.

As we can see in this screenshot, by combining SSH version advertisement and various measured TCP attributes, it is possible to narrow the Linux distribution involved, sometimes down to individual point releases. Even when it is not possible to precisely determine the version, it is almost always possible to determine if the distribution in question is derived from RHEL.

FIGURE 4 – runZero detecting operating systems derived from Red Hat Enterprise Linux.

While determining which RHEL-based distribution an asset is running from just SSH remains unsolved, the work involved resulted in greatly improving the ability to assert the OS family, major version, and sometimes minor versions of the OS. This provides customers insight into the state of their asset fleet as well as the age, support, and end of life status of these assets. The same techniques also allow us to fingerprint other operating systems, such as OpenBSD, down to the specific release version.

Final thought #

Precise fingerprinting is the foundation for delivering actionable asset discovery, exposure management, and attack surface management data to any type of organization. The runZero Research Team’s process behind precise fingerprinting enables security and IT teams to better understand where and when to take action against potential threats in their environments.

Want to learn more about runZero’s unique research on the state of asset security? Check out the runZero Research Report for a deeper look into the drivers behind CAASM.

About Version 2 Limited
Version 2 Digital is one of the most dynamic IT companies in Asia. The company distributes a wide range of IT products across various areas including cyber security, cloud, data protection, end points, infrastructures, system monitoring, storage, networking, business productivity and communication products.

Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which include Global 1000 enterprises, regional listed companies, different vertical industries, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities.

About runZero
runZero, a network discovery and asset inventory solution, was founded in 2018 by HD Moore, the creator of Metasploit. HD envisioned a modern active discovery solution that could find and identify everything on a network–without credentials. As a security researcher and penetration tester, he often employed benign ways to get information leaks and piece them together to build device profiles. Eventually, this work led him to leverage applied research and the discovery techniques developed for security and penetration testing to create runZero.