CVE-2025-67742 is a path traversal vulnerability identified in JetBrains TeamCity, a popular continuous integration and build management system. The flaw exists in versions prior to 2025.11 and allows an authenticated user with high privileges to exploit the file upload functionality to perform directory traversal attacks. This means an attacker can craft file upload requests that escape the intended upload directory and write files to arbitrary locations on the server's file system. The vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), indicating insufficient validation or sanitization of file paths during upload processing. The CVSS 3.1 base score is 3.8, reflecting a low severity primarily because exploitation requires privileged authentication (PR:H), no user interaction (UI:N), and the impact is limited to integrity and availability (I:L, A:L) without confidentiality loss. The vulnerability could allow overwriting critical configuration or executable files, potentially causing service disruption or unauthorized code execution if combined with other vulnerabilities. No public exploits have been reported yet, and no official patches are linked at this time, but JetBrains has reserved the CVE and published the advisory. The vulnerability affects all versions before 2025.11, so upgrading to the fixed version is the primary remediation step.

For European organizations, the impact of CVE-2025-67742 is primarily on the integrity and availability of TeamCity servers. Successful exploitation could allow attackers with high-level access to overwrite or create files outside the intended directories, potentially disrupting build pipelines, corrupting build artifacts, or causing denial of service. While confidentiality is not directly impacted, the disruption to continuous integration workflows could delay software development and deployment, affecting business operations. Organizations relying heavily on TeamCity for critical software delivery, especially in regulated industries such as finance, healthcare, or critical infrastructure, may face operational risks and compliance challenges. The requirement for privileged authentication limits the attack surface to insiders or compromised accounts, but insider threats or lateral movement by attackers could leverage this vulnerability. Given the widespread use of TeamCity in European software development environments, the vulnerability could have a broad impact if left unmitigated.

1. Upgrade TeamCity to version 2025.11 or later as soon as the patch is available to ensure the vulnerability is fully remediated. 2. Until patching, restrict file upload permissions to the minimum necessary users and roles, limiting exposure to privileged accounts only. 3. Implement strict input validation and sanitization on file upload paths, if custom plugins or integrations are used. 4. Monitor file system activity on TeamCity servers for unusual file creation or modification outside expected directories, using host-based intrusion detection systems or file integrity monitoring tools. 5. Enforce strong authentication and access controls to reduce the risk of privilege abuse or compromise. 6. Conduct regular audits of user permissions and review logs for suspicious activity related to file uploads. 7. Isolate TeamCity servers in segmented network zones to limit lateral movement in case of compromise. 8. Educate administrators and developers about the risks of path traversal vulnerabilities and secure coding practices.