CVE-2023-40342 in Flaky Test Handler Plugin
Summary
by MITRE • 08/16/2023
Jenkins Flaky Test Handler Plugin 1.2.2 and earlier does not escape JUnit test contents when showing them on the Jenkins UI, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers able to control JUnit report file contents.
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Analysis
by VulDB Data Team • 09/10/2023
The vulnerability identified as CVE-2023-40342 affects the Jenkins Flaky Test Handler Plugin version 1.2.2 and earlier, presenting a critical stored cross-site scripting flaw that directly impacts the security posture of Jenkins environments. This issue arises from insufficient input validation and output sanitization within the plugin's handling of JUnit test report contents, creating an avenue for malicious actors to inject arbitrary web scripts into the Jenkins user interface. The vulnerability is particularly concerning because it allows attackers who can influence JUnit report file contents to execute persistent XSS attacks against other users who view these test results within the Jenkins UI.
The technical exploitation of this vulnerability stems from the plugin's failure to properly escape or sanitize JUnit test content before rendering it in the web interface. When Jenkins processes JUnit test reports, the plugin displays test names, descriptions, and other metadata directly in the UI without adequate HTML escaping or content sanitization. This design flaw creates a stored XSS vector where malicious payloads embedded within test reports can be executed whenever legitimate users access the affected plugin interface. The vulnerability is classified as stored XSS because the malicious content is permanently stored within the Jenkins system and executed against users who view the affected pages, rather than requiring a one-time injection.
The operational impact of CVE-2023-40342 extends beyond simple script execution, as it provides attackers with potential access to sensitive Jenkins environments and data. Successful exploitation could enable attackers to steal session cookies, perform unauthorized actions on behalf of legitimate users, access confidential build information, or even escalate privileges within the Jenkins infrastructure. The vulnerability is particularly dangerous in enterprise environments where Jenkins is used for continuous integration and deployment processes, as it could compromise the integrity of the entire software development lifecycle. Attackers could leverage this vulnerability to gain persistent access to Jenkins systems and potentially access source code repositories, build artifacts, and other sensitive operational data.
This vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and demonstrates a clear violation of secure coding practices for input validation and output encoding. From an ATT&CK framework perspective, this vulnerability maps to T1566.001 (Phishing via Social Engineering) and T1078 (Valid Accounts) as attackers could use the XSS to steal user credentials or escalate privileges. The attack surface is particularly broad since JUnit reports are commonly generated and stored as part of standard CI/CD pipelines, making this vulnerability potentially exploitable in numerous Jenkins installations. Organizations should prioritize patching this vulnerability immediately, as the plugin's widespread use across development environments means that many systems could be at risk.
Mitigation strategies for CVE-2023-40342 should include immediate upgrade to Jenkins Flaky Test Handler Plugin version 1.2.3 or later, which contains the necessary fixes to properly escape JUnit content before UI rendering. Additionally, organizations should implement network-level restrictions to limit access to Jenkins systems, particularly for users who do not require full administrative privileges. Security teams should also consider implementing content security policies and monitoring for suspicious JUnit report uploads to detect potential exploitation attempts. Regular security assessments of Jenkins plugins and configurations should be conducted to identify similar vulnerabilities, as this issue demonstrates the importance of proper input sanitization in web-based continuous integration platforms. The vulnerability serves as a reminder of the critical need for secure coding practices in plugin development and the importance of validating all user-supplied content before rendering it in web interfaces.