CVE-2022-34787 in Project Inheritance Plugin
Summary
by MITRE • 06/30/2022
Jenkins Project Inheritance Plugin 21.04.03 and earlier does not escape the reason a build is blocked in tooltips, resulting in a cross-site scripting (XSS) vulnerability exploitable by attackers able to control the reason a queue item is blocked.
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Analysis
by VulDB Data Team • 07/17/2022
The Jenkins Project Inheritance Plugin vulnerability CVE-2022-34787 represents a critical cross-site scripting flaw that emerged in versions 21.04.03 and earlier. This vulnerability stems from insufficient input validation and output encoding within the plugin's tooltip functionality, creating an avenue for malicious code execution when build queue items are blocked. The flaw specifically affects the plugin's handling of user-controllable data that appears in tooltips, which are contextual UI elements displayed when users hover over queue items. Attackers who can influence the reason a build is blocked can inject malicious scripts into these tooltips, potentially compromising user sessions and system integrity.
The technical implementation of this vulnerability resides in the plugin's failure to properly escape special characters when rendering tooltip content. When a build queue item becomes blocked, the system displays a tooltip containing information about the blocking reason, but this content is not adequately sanitized before being rendered in the browser. This omission allows attackers to inject script tags, event handlers, or other malicious payloads that execute within the context of the victim's browser session. The vulnerability is particularly dangerous because it requires minimal privileges to exploit, as attackers only need to be able to control the blocking reason rather than having full administrative access to the Jenkins instance.
The operational impact of CVE-2022-34787 extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal sensitive credentials, or redirect users to malicious domains. Since Jenkins is commonly used in continuous integration and deployment pipelines, this vulnerability could compromise the entire software development lifecycle. An attacker could inject malicious code that steals authentication tokens, modifies build results, or even escalates privileges within the Jenkins environment. The vulnerability also poses risks to the broader network infrastructure, as compromised Jenkins instances often have elevated access to other systems and services within the organization's ecosystem. This aligns with ATT&CK technique T1078.004 for valid accounts and T1566.001 for spearphishing attachments, as the exploitation could lead to further lateral movement and credential theft.
Organizations should immediately upgrade to a patched version of the Jenkins Project Inheritance Plugin to remediate this vulnerability. The mitigation strategy should include implementing proper input validation and output encoding practices, specifically ensuring that all user-controllable data displayed in tooltips and other UI elements is properly escaped before rendering. Security teams should also consider implementing content security policies to further reduce the impact of potential XSS attacks. Regular security assessments of Jenkins plugins and configurations are essential to identify similar vulnerabilities in other components. This vulnerability demonstrates the critical importance of input sanitization and output encoding in web applications, as outlined in CWE-79, which specifically addresses cross-site scripting vulnerabilities. The incident underscores the need for comprehensive security testing of all user-facing interfaces and the implementation of robust defense-in-depth strategies to protect CI/CD environments from malicious exploitation attempts.