CVE-2025-36159 is a vulnerability identified in IBM Concert versions 1.0.0 through 2.0.0, classified under CWE-117, which refers to improper output neutralization for logs. This vulnerability arises because the software fails to properly sanitize or neutralize user-controlled input before writing it to log files. As a result, a local attacker with access to the system can craft malicious input that, when logged, can forge or manipulate log entries. This manipulation can allow the attacker to impersonate other users within the logs or erase traces of their own actions, thereby undermining the integrity and reliability of audit trails. The CVSS 3.1 base score of 6.2 reflects a medium severity level, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), high integrity impact (I:H), and no availability impact (A:N). The vulnerability does not expose sensitive data but compromises the trustworthiness of logs, which are essential for incident response and compliance auditing. No public exploits or patches are currently available, emphasizing the need for proactive mitigation. The vulnerability is particularly concerning in environments where log integrity is critical for security monitoring and regulatory compliance.

For European organizations, the primary impact of CVE-2025-36159 is the potential compromise of log integrity, which can severely hinder incident detection, forensic investigations, and compliance with regulations such as GDPR and NIS Directive. Attackers exploiting this vulnerability can cover their tracks by forging logs, making it difficult to attribute malicious activities or detect insider threats. This risk is heightened in sectors like finance, healthcare, and critical infrastructure, where accurate logging is mandated. Although the vulnerability requires local access, insider threats or attackers who have gained initial footholds could leverage this to evade detection. The absence of confidentiality or availability impacts means data breaches or service disruptions are unlikely directly from this flaw, but the indirect effects on security monitoring could lead to broader compromises. European organizations relying on IBM Concert for collaboration or project management may face increased risk of undetected malicious activity, potentially leading to regulatory penalties and reputational damage.

To mitigate CVE-2025-36159, European organizations should implement strict access controls to limit local user access to systems running IBM Concert, ensuring only trusted personnel can interact with the software. Employ enhanced monitoring and alerting for unusual log patterns or inconsistencies that may indicate log forgery attempts. Maintain comprehensive backups of log files to enable comparison and detection of tampering. Until IBM releases a patch, consider isolating IBM Concert instances in segmented network zones with restricted user access. Conduct regular audits of log integrity using cryptographic techniques such as log signing or hash chaining if supported by the environment. Educate system administrators and security teams about the risks of log manipulation and the importance of verifying log authenticity. Finally, stay informed on IBM’s advisories for patches or updates addressing this vulnerability and apply them promptly upon release.