CVE-2021-37198 is a high-severity vulnerability affecting Siemens COMOS software versions 10.2, 10.3 (prior to 10.3.3.3), and 10.4 (prior to 10.4.1) when their web components are used. The vulnerability is classified as CWE-352, indicating a Cross-Site Request Forgery (CSRF) flaw. CSRF vulnerabilities occur when a web application does not adequately verify that requests made to it originate from authenticated and authorized users, allowing attackers to trick victims into submitting unwanted actions. In this case, the COMOS Web component implements flawed CSRF prevention mechanisms, which could allow an attacker to craft malicious web requests that, when executed by an authenticated user’s browser, perform unauthorized actions on the COMOS system without the user’s consent or knowledge. The CVSS v3.1 base score of 8.8 reflects the critical nature of this vulnerability, with an attack vector of network (remote exploitation), low attack complexity, no privileges required, but requiring user interaction (the victim must visit a malicious site or click a crafted link). The impact is severe, affecting confidentiality, integrity, and availability of the system, as unauthorized commands could lead to data disclosure, modification, or disruption of services. Siemens COMOS is an engineering software suite widely used in industrial sectors for plant engineering and operations, often integrated with critical infrastructure systems. The lack of effective CSRF protection in web components exposes these environments to potential unauthorized manipulations, which could have cascading effects on industrial processes and safety. No known exploits are currently reported in the wild, but the vulnerability’s characteristics make it a significant risk if weaponized.

For European organizations, especially those in industrial manufacturing, energy, utilities, and infrastructure sectors that rely on Siemens COMOS for plant engineering and operational management, this vulnerability poses a substantial risk. Exploitation could allow attackers to perform unauthorized actions such as altering engineering data, changing operational parameters, or disrupting workflows, potentially leading to operational downtime, safety hazards, and loss of sensitive intellectual property. Given the critical role of COMOS in managing complex industrial environments, successful attacks could impact production continuity and regulatory compliance. The high CVSS score indicates that the vulnerability could be exploited remotely without credentials, increasing the attack surface. European organizations with web-accessible COMOS components are particularly vulnerable if users can be tricked into visiting malicious websites or clicking malicious links, which is a common attack vector. The absence of known exploits suggests a window of opportunity for proactive mitigation before widespread exploitation occurs.

1. Immediate application of Siemens-provided patches or updates to COMOS versions 10.3.3.3 or later and 10.4.1 or later, which address the CSRF prevention flaws, is critical. If patches are not yet available, consider disabling or restricting access to the web components of COMOS until remediation is possible. 2. Implement network-level protections such as web application firewalls (WAFs) configured to detect and block CSRF attack patterns and suspicious cross-origin requests targeting COMOS web endpoints. 3. Enforce strict access controls and segmentation to limit exposure of COMOS web interfaces to trusted internal networks or VPNs, reducing the risk of external exploitation. 4. Conduct user awareness training focused on phishing and social engineering to reduce the likelihood of users interacting with malicious links or websites that could trigger CSRF attacks. 5. Monitor logs and network traffic for unusual or unauthorized requests to COMOS web components, enabling early detection of attempted exploitation. 6. Employ multi-factor authentication (MFA) where possible to add an additional layer of security, although MFA alone does not prevent CSRF, it can reduce overall risk. 7. Review and enhance application-level CSRF protections, such as implementing anti-CSRF tokens and validating the Origin and Referer headers, to ensure robust defense against forgery attacks.