CVE-2025-64139 is a vulnerability identified in the Jenkins Start Windocks Containers Plugin version 1.4 and earlier. The root cause is a missing permission check that allows users who possess Overall/Read permissions within Jenkins to initiate connections to attacker-controlled URLs. This vulnerability is classified under CWE-862 (Missing Authorization) and does not require user interaction to exploit. The attacker leverages the insufficient authorization to cause Jenkins to connect to arbitrary URLs, which could be used for various malicious purposes such as SSRF (Server-Side Request Forgery), data exfiltration, or pivoting within a network. The CVSS v3.1 score is 4.3 (medium severity), reflecting that the attack vector is network-based, requires low attack complexity, and privileges equivalent to Overall/Read permissions, but does not impact confidentiality or availability directly. The vulnerability affects all versions up to 1.4 of the plugin, which is used to start Windocks containers from Jenkins, a common CI/CD automation tool. No patches or exploits are currently reported, but the flaw represents a risk in environments where users have read-level access but should not be able to influence network connections. This vulnerability highlights the importance of strict permission checks in plugins that interact with external resources or network services.

For European organizations, this vulnerability poses a moderate risk primarily to the integrity of Jenkins environments. Attackers with Overall/Read permissions could exploit this flaw to make Jenkins connect to malicious URLs, potentially leading to SSRF attacks, internal network reconnaissance, or indirect data leakage. While confidentiality and availability are not directly impacted, the integrity of build and deployment pipelines could be compromised, affecting software delivery and operational reliability. Organizations heavily reliant on Jenkins for DevOps automation, especially those integrating containerized workflows with Windocks, are at greater risk. This could impact sectors such as finance, manufacturing, and technology where continuous integration and deployment are critical. The vulnerability could also be leveraged as a foothold for further lateral movement within corporate networks. Given the medium severity and no known exploits, the immediate risk is moderate but should not be underestimated in sensitive or highly regulated environments.

To mitigate this vulnerability, European organizations should first audit and restrict Overall/Read permissions in Jenkins to only trusted users, minimizing the attack surface. Network-level controls should be implemented to monitor and restrict outbound connections from Jenkins servers, especially to untrusted or external URLs. Organizations should enforce strict plugin update policies and apply patches as soon as they become available from the Jenkins project. Until a patch is released, consider disabling or removing the Start Windocks Containers Plugin if it is not essential. Additionally, implement network segmentation to isolate Jenkins servers from sensitive internal resources. Employ logging and alerting on unusual network activity originating from Jenkins to detect potential exploitation attempts early. Finally, review and harden Jenkins security configurations, including the use of Role-Based Access Control (RBAC) and credential management best practices.