CVE-2023-31238 is a vulnerability classified under CWE-732 (Incorrect Permission Assignment for Critical Resource) found in Siemens SICAM P850 and P855 series devices, specifically all versions prior to 3.11. These devices are widely used in industrial control systems, particularly in energy distribution and automation sectors. The vulnerability stems from missing cookie protection flags (such as Secure, HttpOnly, or SameSite) in the default configuration, which are critical for securing session tokens against interception or misuse. Without these flags, session tokens can be exposed to theft via network attacks like man-in-the-middle or cross-site scripting if an attacker gains network access or tricks a user into interaction. Once a session token is compromised, the attacker can impersonate a legitimate application user, potentially accessing sensitive control functions or data. The CVSS 3.1 score is 5.5 (medium), reflecting network attack vector, high attack complexity, low privileges required, and user interaction needed. The impact on confidentiality, integrity, and availability is limited but non-negligible due to the critical nature of the systems involved. No public exploits or active exploitation have been reported, but the vulnerability poses a risk to operational technology environments where these devices are deployed. Siemens has not yet provided a patch link in the data, but upgrading to version 3.11 or later is recommended. The vulnerability highlights the importance of secure session management in industrial control systems.

For European organizations, particularly those operating critical infrastructure such as energy utilities, this vulnerability could allow attackers to impersonate legitimate users of SICAM P850/P855 devices, potentially leading to unauthorized access to control systems. This could result in manipulation or disruption of energy distribution processes, causing operational outages or safety hazards. Although the vulnerability requires user interaction and has a medium severity rating, the strategic importance of these devices in European energy grids elevates the risk. Confidentiality breaches could expose sensitive operational data, while integrity and availability impacts could disrupt service continuity. The lack of cookie protection flags increases the risk of session hijacking attacks, especially in environments with insufficient network segmentation or monitoring. The absence of known exploits reduces immediate risk but does not eliminate the threat, as attackers could develop exploits targeting this vulnerability. Organizations relying on Siemens SICAM devices must consider this vulnerability in their risk assessments and incident response planning.

1. Upgrade all affected Siemens SICAM P850 and P855 devices to firmware version 3.11 or later as soon as it becomes available, as this version addresses the cookie protection flag issues. 2. Until patching is possible, implement strict network segmentation to isolate SICAM devices from general IT networks and limit access to trusted personnel only. 3. Enforce multi-factor authentication and strong session management policies on systems interfacing with SICAM devices to reduce the risk of session token compromise. 4. Monitor network traffic for unusual session token usage or repeated authentication failures that could indicate session hijacking attempts. 5. Configure web application firewalls or intrusion detection systems to detect and block attempts to exploit session management weaknesses. 6. Educate users and administrators about phishing and social engineering risks that could lead to session token theft. 7. Regularly audit and review device configurations to ensure cookie flags (Secure, HttpOnly, SameSite) are properly set once patches are applied. 8. Collaborate with Siemens support for guidance and timely updates regarding this vulnerability.