CVE-2022-29831 is a vulnerability identified in Mitsubishi Electric Corporation's GX Works3 software, specifically affecting versions from 1.015R to 1.095Z. GX Works3 is an engineering software suite used for programming and configuring MELSEC programmable logic controllers (PLCs), including safety CPU modules, which are critical components in industrial automation and control systems. The vulnerability arises from the use of a hard-coded password within the software, classified under CWE-259 (Use of Hard-coded Password). This flaw allows a remote, unauthenticated attacker to exploit the embedded password to gain unauthorized access to sensitive project files related to MELSEC safety CPU modules. These project files contain configuration and operational data essential for the proper functioning and safety of industrial control processes. Since the attacker does not require authentication or user interaction, the attack vector is relatively straightforward, increasing the risk of exploitation. Although no known exploits have been reported in the wild, the presence of a hard-coded password significantly undermines the confidentiality and integrity of the affected systems. The vulnerability does not directly cause denial of service or system disruption but could lead to information disclosure that may facilitate further attacks or manipulation of safety-critical systems. The lack of an available patch at the time of reporting further elevates the urgency for mitigation efforts.

For European organizations, particularly those operating in industrial sectors such as manufacturing, energy, transportation, and critical infrastructure, this vulnerability poses a significant risk. The disclosure of project files for MELSEC safety CPU modules could enable attackers to understand and potentially manipulate safety logic, leading to unsafe operational states or sabotage. This compromises the integrity and safety of industrial processes, potentially causing physical damage, safety incidents, or production downtime. Confidentiality breaches could expose proprietary process designs or safety configurations, resulting in intellectual property loss and competitive disadvantage. Given the reliance on Mitsubishi Electric's automation products across Europe, especially in countries with advanced manufacturing sectors, the vulnerability could have widespread operational and safety implications. Furthermore, the vulnerability could be leveraged as a foothold for more sophisticated attacks targeting industrial control systems (ICS), increasing the risk of cascading failures or targeted cyber-physical attacks.

Organizations should immediately conduct an inventory to identify all instances of GX Works3 within their environments and verify the versions in use. Since no official patch is available, mitigating controls should include restricting network access to engineering workstations running GX Works3, especially from untrusted networks. Implement strict network segmentation and firewall rules to isolate industrial control networks from corporate and external networks. Employ intrusion detection and prevention systems (IDS/IPS) tuned to detect anomalous access attempts to GX Works3 project files. Enforce strong access controls and monitor for unauthorized access or exfiltration of project files. Consider using application whitelisting and endpoint protection solutions to prevent unauthorized execution of tools that might exploit the vulnerability. Additionally, coordinate with Mitsubishi Electric for updates or patches and plan for timely deployment once available. Conduct security awareness training for personnel involved in industrial control system management to recognize and report suspicious activities. Finally, review and enhance incident response plans to address potential exploitation scenarios involving industrial safety systems.