Security Experts:

Connect with us

Hi, what are you looking for?



Vulnerability in Mitsubishi Controllers Can Allow Hackers to Disrupt Production

A potentially serious denial-of-service (DoS) vulnerability affecting some Mitsubishi Electric automation controllers can allow hackers to disrupt the production process in an industrial organization, experts have warned.

A potentially serious denial-of-service (DoS) vulnerability affecting some Mitsubishi Electric automation controllers can allow hackers to disrupt the production process in an industrial organization, experts have warned.

The flaw, discovered by a researcher at industrial cybersecurity firm SCADAfence and reported to Mitsubishi in late February, was described by the vendor as an uncontrolled resource consumption issue that allows an attacker to cause the Ethernet port to enter a DoS condition by sending it specially crafted packets, in bursts, over a short period of time.

The vulnerability affects Mitsubishi’s MELSEC iQ-R series CPU modules, including R00, R04 and R08, and the RJ71EN71 Ethernet interface module. The vendor has released firmware updates that should address the flaw for several of the affected modules and plans on releasing patches for the remaining products “soon.” In the meantime, the company recommends a series of mitigation steps.

Mitsubishi controller vulnerability

Ofer Shaked, co-founder and CTO of SCADAfence, told SecurityWeek that the impacted controllers are used across all industries. The affected products include safety controllers, high-speed motion controllers used in robotics and other motion-oriented applications, and process CPUs that can be used to monitor and control physical processes in sectors such as critical infrastructure and manufacturing.

Learn More About Vulnerabilities in Industrial Products at SecurityWeek’s ICS Cyber Security Conference and SecurityWeek’s Security Summits Virtual Event Series

“This vulnerability is dangerous to industrial environments, because unlike other DoS attacks, it doesn’t only crash the network interface controller. We’re also talking about crashing the main CPU, which stops the entire production process and loses the current state of operation,” Shaked explained. “An unauthenticated remote attacker over the network, can stop your entire production, in a way that requires physical intervention (rebooting the PLC, recalibrating, restarting any production process).”

Shaked warned that the vulnerability is easy to exploit. Exploitation only requires network access to the targeted device, but no special privileges or user interaction are needed to launch an attack.

“Once an attacker has access to the network, they can run a simple Python script and crash the PLC CPUs remotely. All they need is network connectivity. The script takes less than a second to crash the CPU,” he explained.

He added, “[Exploitation] doesn’t require any advanced knowledge in process automation. The attacker has to send 2 bytes of payload multiple times in burst to the PLC, and the PLC will crash.”

An advisory published by the U.S. Cybersecurity and Infrastructure Security Agency (CISA) assigns the vulnerability a CVSS score of 5.3, which puts it in the medium severity category. However, SCADAfence believes the real CVSS score, based on its impact, is 8.6, which makes it high severity. The company has reached out to CISA in hopes that the CVSS score will be updated in the agency’s advisory.

Related: Critical Flaw in CODESYS Industrial Controller Software Allows Code Execution

Related: Industrial Controllers Still Vulnerable to Stuxnet-Style Attacks

Related: Vulnerabilities in SoftPAC Virtual Controller Expose OT Networks to Attacks

Written By

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Application Security

Drupal released updates that resolve four vulnerabilities in Drupal core and three plugins.

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...


Apple has released updates for macOS, iOS and Safari and they all include a WebKit patch for a zero-day vulnerability tracked as CVE-2023-23529.

Cloud Security

VMware vRealize Log Insight vulnerability allows an unauthenticated attacker to take full control of a target system.

Application Security

A CSRF vulnerability in the source control management (SCM) service Kudu could be exploited to achieve remote code execution in multiple Azure services.

IoT Security

Lexmark warns of a remote code execution (RCE) vulnerability impacting over 120 printer models, for which PoC code has been published.

CISO Strategy

Cybersecurity-related risk is a top concern, so boards need to know they have the proper oversight in place. Even as first-timers, successful CISOs make...