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Ripple20: Mixed Results in SCADAfence’s Exploitability Lab Tests

As part of our mission to secure the world’s OT, IoT and Cyber Physical infrastructures, we invest resources into offensive research of vulnerabilities and attack techniques.

Ripple20 are 19 vulnerabilities revealed by Israeli firm JSOF that affect millions of OT and IOT devices. The vulnerabilities reside in a TCP/IP stack developed by Treck, Inc. The TCP/IP stack is widely used by manufacturers in the OT and IoT industries and thus affects a tremendous amount of devices.

Among the affected devices are Cisco Routers, HP Printers, Digi IoT devices, PLCs by Rockwell Automation and many more. Official advisories by companies who confirmed having affected devices can be found here, in the “More Information” section.

The most critical vulnerabilities are three that can cause a stable Remote Code Execution (CVE-2020-11896, CVE-2020-11897, CVE-2020-11901) and another that can cause the target device’s memory heap to be leaked (CVE-2020-11898).

On behalf of our customers, we set out to explore the real impact of these vulnerabilities, which we’re now sharing with the public.

The research has been conducted by researchers Maayan Fishelov and Dan Haim, and has been managed by SCADAfence’s Co-Founder and CTO, Ofer Shaked.

Exploitability Research
We set out to check the exploitability of these vulnerabilities, starting with CVE-2020-11898 (the heap memory leak vulnerability), one of the 19 published vulnerabilities.

We created a Python POC script that is based on JSOF official whitepaper for this vulnerability. According to JSOF, the implementation is very similar to CVE-2020-11896, which is an RCE vulnerability that is described in the whitepaper. Also mentioned about the RCE vulnerability: “Variants of this Issue can be triggered to cause a Denial of Service or a persistent Denial of Service, requiring a hard reset.”

Trial Results:
Test 1 target: Samsung ProXpress printer model SL-M4070FR firmware version V4.00.02.18 MAY-08-2017. This device is vulnerable according to the HP Advisory.

Test 1 result: The printer’s network crashed and required a hard reset to recover. We were unable to reproduce the heap memory leak as described, and this vulnerability would have been tagged as unauthenticated remote DoS instead, on this specific printer.

Test 2 target: HP printer model M130fw. This device is vulnerable according to the HP Advisory.

Test 2 result: Although reported as vulnerable by the manufacturer, we were unable to reproduce the vulnerability, and we believe that this device isn’t affected by this vulnerability. We believe that’s because the IPinIP feature isn’t enabled on this printer, which we’ve verified with a specially crafted packet.

Test 3 target: Undisclosed at this stage due to disclosure guidelines. We will reveal this finding in the near future.

Test 3 result: We found an unreported vendor and device, on which we can use CVE-2020-11898 to remotely leak 368 bytes from the device’s heap, disclosing sensitive information. No patch is available for this device. Due to our strict policy of using Google’s Responsible Disclosure, we’ve reported this to the manufacturer, to allow them to make a patch available prior to the publication date.

Key Takeaways
We’ve confirmed the exploitability vulnerabilities on our IoT lab devices.

On the negative side: The vulnerabilities exist on additional products that are unknown to the public. Attackers are likely to use this information gap to attack networks.
On the positive side: Some devices that are reported as affected by the manufacturers are actually not affected, or are affected by other vulnerabilities. It might require attackers to tailor their exploits to specific products, increasing the cost of exploitation, and prevent them from using the vulnerability on products that are reported as vulnerable.

SCADAfence Research Recommendations
Check your asset inventory and vulnerability assessment solutions for unpatched products affected by Ripple20.
The SCADAfence Platform creates an asset inventory with product and software versions passively and actively, and allows you to manage your CVEs across all embedded and Windows devices.
Prioritize patching or other mitigation measures based on: Exposure to the internet, exposure to insecure networks (business LAN and others), criticality of the asset.
This prioritization can automatically be obtained from tools such as the SCADAfence Platform.
Detect exploitation based on network traffic analysis.
The SCADAfence Platform detects usage of these exploits in network activity by searching for patterns that indicate usage of this vulnerability in the TCP/IP communications.
If you have any questions or concerns about Ripple20, please contact us and we’ll be happy to assist you and share our knowledge with you or with your security experts.

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 SCADAfence
SCADAfence helps companies with large-scale operational technology (OT) networks embrace the benefits of industrial IoT by reducing cyber risks and mitigating operational threats. Our non-intrusive platform provides full coverage of large-scale networks, offering best-in-class detection accuracy, asset discovery and user experience. The platform seamlessly integrates OT security within existing security operations, bridging the IT/OT convergence gap. SCADAfence secures OT networks in manufacturing, building management and critical infrastructure industries. We deliver security and visibility for some of world’s most complex OT networks, including Europe’s largest manufacturing facility. With SCADAfence, companies can operate securely, reliably and efficiently as they go through the digital transformation journey.

SCADAfence Researchers Discover a Vulnerability in Mitsubishi Electric MELSEC iQ-R Series CPU DoS

As part of our mission to secure the world’s OT, IoT and Cyber Physical infrastructures, we invest resources into offensive research of vulnerabilities and attack techniques.

CVE-2020-13238 is a remote CPU DoS vulnerability in Mitsubishi Electric iQ-R Series that has been discovered by SCADAfence researcher Yossi Reuven.

Mitsubishi Electric is one of the world’s leading electronics and electrical equipment manufacturing companies, and is in use by many of our customers. We have been working with Mitsubishi Electric for the last few months in handling this vulnerability, and on June 9th, Mitsubishi Electric published an official security advisory reporting this vulnerability and mitigations.

CVE-2020-13238

MELSEC iQ-R Series is Mitsubishi Electric flagship product line – design for high productivity automation systems. iQ-R CPUs’ communication with GX Works 3 (Engineering software package) is done via Mitsubishi Electric proprietary protocol MELSOFT (which works on both TCP and UDP). 

When an attacker sends a short burst of specially crafted packets over the MELSOFT UDP protocol on port 5006, which causes the PLC’s CPU to get into fault mode, causing a hardware failure (error code: 0x3C00 – hardware failure). The PLC then becomes unresponsive and requires a manual restart to recover.

What SCADAfence Recommends Vendors To Do

Upgrade to the Latest Firmware

Most of Mitsubishi Electric’s iQ-R Series PLCs are not running on the firmware versions later than Version 40. In addition, automation engineers don’t usually upgrade to the latest firmware, which can lead to their PLCs being exposed to a DoS (denial of service) attack. Upgrading to the latest firmware (Version 49) can prevent this attack from happening.

Block UDP Port 5006 and Use MELSOFT TCP

MELSOFT is an engineering software for Mitsubishi PLCs and gives users the option to use either the (connectionless) UDP and (connection-oriented) TCP protocols for programming and configuring the devices. SCADAfence recommends to block Block UDP port 5006 since the cyberattack leverages the connectionless UDP protocol and can cause the PLCs to stop functioning and cause a denial of service. Instead, users should use the TCP protocol for communicating with devices in the shop floor or the control network.

Special Thanks & Recognition

The SCADAfence Research team would like to thank the Mitsubishi Electric team for a speedy vulnerability reporting process even during the challenging COVID-19 times.

SCADAfence is committed to continued research of offensive technologies and development of new defensive technologies.

Exploit PoC

We wrote a Python POC (GPLv3) script of the exploit in action. You can download it for free and use this for educational / research purposes.

Warning: The script will crash the PLC’s CPU – don’t use in production.

To get this free python script, please send an email to christoph@scadafence.com

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 SCADAfence
SCADAfence helps companies with large-scale operational technology (OT) networks embrace the benefits of industrial IoT by reducing cyber risks and mitigating operational threats. Our non-intrusive platform provides full coverage of large-scale networks, offering best-in-class detection accuracy, asset discovery and user experience. The platform seamlessly integrates OT security within existing security operations, bridging the IT/OT convergence gap. SCADAfence secures OT networks in manufacturing, building management and critical infrastructure industries. We deliver security and visibility for some of world’s most complex OT networks, including Europe’s largest manufacturing facility. With SCADAfence, companies can operate securely, reliably and efficiently as they go through the digital transformation journey.