Two potentially serious vulnerabilities have been found in factory automation products made by Japanese electronics and electrical equipment manufacturing firm Mitsubishi Electric.
In an advisory published last week, Mitsubishi Electric said several factory automation (FA), products are impacted by a high-severity authentication bypass and a critical remote code execution vulnerability.
Impacted products include EZSocket, FR Configurator2, GT Designer3, GX and MT Works, MELSOFT Navigator, and MX.
“A remote unauthenticated attacker may be able to bypass authentication by sending specially crafted packets and connect to the products illegally (CVE-2023-6942),” the vendor explained. “Furthermore, the attacker may be able to execute a malicious code by remotely calling a function with a path to a malicious library while connected to the products (CVE-2023-6943). As a result, unauthorized users may disclose, tamper with, destroy or delete information in the products, or cause a denial-of-service (DoS) condition on the products.”
The company has yet to release patches. Users of the impacted products have been advised to implement general cybersecurity measures to reduce the risk of exploitation.
Reid Wightman, vulnerability analyst at industrial cybersecurity firm Dragos, who has been credited with reporting the issues to Mitsubishi, told SecurityWeek that the flaws could be exploited directly from the internet, but it’s unclear if any systems are directly accessible from the web.
“This is a proprietary network protocol, and search engines such as Shodan do not look for the exposed service presently. While we hope that nobody who uses this software is exposing their computers to the Internet directly, these things do sometimes happen,” Wightman explained.
As for potential impact in a real world attack scenario, the researcher explained, “If an attacker targets these systems, they will gain high-privileged access to an engineering workstation. This means the attacker can likely communicate with and reprogram PLCs, as well as install new utilities on the engineering workstation.”
Engineering workstations have been used as an initial access vector in many attacks aimed at organizations with industrial control systems (ICS) and other operational technology (OT) environments.
The US security agency CISA has also published an advisory to inform industrial organizations about these vulnerabilities.
On the same day, Mitsubishi and CISA also published advisories describing another authentication bypass issue, one affecting MELSEC WS series Ethernet interface modules. However, this flaw only has a severity rating of ‘medium’ because exploitation involves a man-in-the-middle attack.
“A remote unauthenticated attacker can bypass authentication by capture-replay attack and illegally login to the modules. As a result, the remote attacker who has logged in illegally may be able to disclose or tamper with the programs and parameters in the modules,” the vendor said.
It’s worth noting that Mitsubishi Electric appears to be putting a lot of effort into addressing vulnerabilities found in its products. The company last year released 36 security advisories and a high number of advisories is typically an indicator that the company takes vulnerability reports seriously.