CVE-2025-64133 identifies a cross-site request forgery (CSRF) vulnerability in the Jenkins Extensible Choice Parameter Plugin, specifically version 239.v5f5c278708cf and earlier. This vulnerability allows an attacker to execute sandboxed Groovy code remotely by tricking a Jenkins user into performing an unintended action via a crafted request. The plugin is used to provide dynamic choice parameters in Jenkins jobs, and the CSRF flaw arises because the plugin fails to properly validate the origin of requests, allowing unauthorized commands to be executed in the context of the Jenkins server. The vulnerability does not require any authentication or privileges (PR:N), but does require user interaction (UI:R), meaning an attacker must convince a user to visit a malicious page or click a crafted link. The attack vector is network-based (AV:N), and the complexity is low (AC:L), indicating ease of exploitation. While confidentiality is not impacted, the integrity and availability of Jenkins jobs and environments can be compromised by executing arbitrary Groovy scripts, potentially leading to unauthorized changes or disruption of CI/CD pipelines. No patches or fixes have been released at the time of publication, and no known exploits have been observed in the wild. The vulnerability is classified under CWE-352 (Cross-Site Request Forgery).

For European organizations, this vulnerability poses a significant risk to the integrity and availability of Jenkins-based continuous integration and deployment pipelines. Exploitation could allow attackers to execute arbitrary Groovy code within Jenkins, potentially modifying build parameters, injecting malicious code into software builds, or disrupting automated workflows. This could lead to compromised software supply chains, unauthorized code changes, or denial of service conditions in critical development environments. Organizations relying heavily on Jenkins for DevOps automation, especially those in regulated industries such as finance, healthcare, and critical infrastructure, may face operational disruptions and compliance risks. The lack of confidentiality impact reduces the risk of data leakage but does not mitigate the threat to system integrity and availability. The medium CVSS score reflects these concerns, emphasizing the need for timely mitigation to avoid exploitation.

Until an official patch is released, European organizations should implement several specific mitigations: 1) Restrict access to Jenkins interfaces by enforcing strict network segmentation and firewall rules to limit exposure to trusted users only. 2) Disable or uninstall the Extensible Choice Parameter Plugin if it is not essential to operations. 3) Enforce multi-factor authentication and strong user access controls to reduce the risk of successful social engineering attacks that enable CSRF exploitation. 4) Educate Jenkins users about the risks of clicking unknown links or visiting untrusted websites while logged into Jenkins. 5) Monitor Jenkins logs for unusual Groovy script executions or unexpected job parameter changes that could indicate exploitation attempts. 6) Prepare for rapid deployment of patches once available by maintaining an up-to-date inventory of Jenkins plugins and versions. 7) Consider implementing web application firewalls (WAFs) with CSRF protection capabilities to detect and block suspicious requests targeting Jenkins endpoints. These measures go beyond generic advice by focusing on access control, user behavior, and proactive monitoring tailored to the Jenkins environment.