CVE-2025-64645 is a vulnerability classified under CWE-367, representing a time-of-check to time-of-use (TOCTOU) race condition in IBM Concert versions 1.0.0 through 2.1.0. The flaw stems from improper handling of symbolic links during privilege-sensitive operations. Specifically, the software performs a security check on a file or resource and then uses it without revalidating, allowing a local attacker to exploit the timing gap by substituting a symbolic link between the check and use phases. This can lead to unauthorized privilege escalation, granting the attacker higher system privileges than intended. The CVSS v3.1 base score is 7.7, reflecting high impact on confidentiality and integrity, with low attack complexity and no privileges or user interaction required. Although no public exploits are currently known, the vulnerability's nature makes it a critical concern for environments where IBM Concert is deployed. The absence of available patches at the time of publication necessitates immediate risk mitigation through operational controls and monitoring. The vulnerability affects local users, emphasizing the need for strict local access controls and auditing.

For European organizations, this vulnerability poses a significant risk of local privilege escalation, potentially allowing attackers with limited access to gain administrative control over systems running IBM Concert. This can lead to unauthorized data access, modification, or disruption of services, impacting confidentiality and integrity. Sectors such as finance, manufacturing, and critical infrastructure that rely on IBM Concert for orchestration or automation may face operational disruptions or data breaches. The local nature of the attack vector means insider threats or compromised user accounts could exploit this flaw. Given the high CVSS score and the critical nature of privilege escalation, organizations could face regulatory and compliance repercussions under GDPR if sensitive data is exposed or integrity is compromised. The lack of known exploits currently provides a window for proactive defense, but the vulnerability's characteristics suggest it could be weaponized quickly once exploit code becomes available.

1. Immediately restrict local user permissions to the minimum necessary, especially on systems running IBM Concert, to reduce the attack surface. 2. Implement strict file system monitoring and alerting for suspicious symbolic link creation or modification activities, using tools like auditd or equivalent. 3. Employ application whitelisting and integrity checking to detect unauthorized changes to IBM Concert binaries or related files. 4. Isolate IBM Concert servers from general user environments to limit local access. 5. Regularly review and harden local access policies and user group memberships to prevent unauthorized local user creation or privilege escalation. 6. Monitor vendor communications closely for patches or updates addressing CVE-2025-64645 and apply them promptly once released. 7. Conduct internal penetration testing or red team exercises simulating TOCTOU attacks to validate defenses. 8. Educate system administrators and security teams about the nature of TOCTOU vulnerabilities and the importance of timely mitigation.