CVE-2023-46650 in GitHub Plugin
Summary
by MITRE • 10/25/2023
Jenkins GitHub Plugin 1.37.3 and earlier does not escape the GitHub project URL on the build page when showing changes, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Item/Configure permission.
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Analysis
by VulDB Data Team • 11/16/2023
The vulnerability identified as CVE-2023-46650 affects the Jenkins GitHub Plugin version 1.37.3 and earlier, presenting a critical stored cross-site scripting vulnerability that can be exploited by attackers possessing Item/Configure permissions. This flaw resides in how the plugin handles GitHub project URLs displayed on build pages, specifically failing to properly escape these URLs before rendering them in the user interface. The vulnerability demonstrates characteristics consistent with CWE-79, which defines stored cross-site scripting as a type of security flaw where malicious scripts are stored on a server and executed when users access affected pages. The issue is particularly concerning in Jenkins environments where multiple users may have varying permission levels, as it provides a vector for attackers to potentially escalate privileges or access sensitive information through malicious script injection.
The technical implementation of this vulnerability stems from the plugin's inadequate input validation and output escaping mechanisms when processing GitHub project URLs. When Jenkins displays build changes and includes references to GitHub project URLs, the plugin fails to sanitize these inputs before rendering them in HTML contexts. This creates an environment where attackers can inject malicious JavaScript code into project URLs, which then gets executed whenever other users view the build page containing these stored URLs. The vulnerability requires only Item/Configure permission, which is often granted to developers and team members who need to modify job configurations, making it particularly dangerous in environments where such permissions are widely distributed.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration from Jenkins environments. An attacker who successfully exploits this vulnerability can manipulate the build display pages to execute arbitrary JavaScript code in the context of other users' browsers, potentially allowing them to access Jenkins configuration data, view sensitive build artifacts, or even modify job parameters. This stored XSS vulnerability operates through a persistent attack vector where malicious payloads are stored on the server and executed automatically when users access affected pages, making detection and mitigation more challenging compared to reflected XSS attacks. The attack surface is further expanded by the fact that Jenkins is commonly used in continuous integration and deployment pipelines where build information is frequently accessed by multiple stakeholders.
Mitigation strategies for CVE-2023-46650 should prioritize immediate patching of the Jenkins GitHub Plugin to version 1.37.4 or later, which contains the necessary fixes for proper URL escaping. Organizations should also implement additional security controls including input validation for all user-provided URLs, regular security scanning of Jenkins plugins, and monitoring for suspicious configuration changes. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to prevent script execution in Jenkins environments. Security teams should conduct comprehensive audits of Jenkins plugin configurations and permissions, ensuring that users with Item/Configure permissions are properly vetted and that least privilege principles are enforced. This vulnerability also highlights the importance of maintaining up-to-date security practices in CI/CD environments, where tools like Jenkins serve as critical infrastructure components that require continuous security monitoring and patch management. The ATT&CK framework categorizes this vulnerability under T1566 - Phishing and T1059 - Command and Scripting Interpreter, emphasizing the potential for attackers to leverage such vulnerabilities for initial access and execution within Jenkins environments.