CVE-2020-2194 in ECharts API Plugin
Summary
by MITRE
Jenkins ECharts API Plugin 4.7.0-3 and earlier does not escape the display name of the builds in the trend chart, resulting in a stored cross-site scripting vulnerability.
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Analysis
by VulDB Data Team • 06/04/2020
The vulnerability identified as CVE-2020-2194 affects the Jenkins ECharts API Plugin version 4.7.0-3 and earlier, presenting a critical stored cross-site scripting vulnerability that compromises the security of Jenkins environments. This issue arises from the plugin's failure to properly sanitize user-supplied display names when rendering trend charts, creating a persistent vector for malicious code execution within the Jenkins interface. The flaw specifically impacts the visualization component of Jenkins build monitoring, where user-generated content is directly embedded into HTML output without appropriate encoding or escaping mechanisms.
The technical root cause of this vulnerability stems from inadequate input validation and output sanitization within the plugin's rendering logic. When Jenkins administrators or users create build jobs with custom display names containing malicious script code, the ECharts plugin fails to escape these inputs before displaying them in trend charts. This stored XSS vulnerability allows attackers to inject malicious JavaScript code that executes in the context of other users' browsers when they view the affected charts. The vulnerability is classified under CWE-79 as a failure to escape output, specifically manifesting as a stored cross-site scripting flaw that persists across multiple user sessions.
The operational impact of CVE-2020-2194 extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal sensitive credentials, access restricted build data, or even escalate privileges within the Jenkins environment. An attacker who can influence build display names through legitimate means or by exploiting other vulnerabilities can craft malicious entries that will execute whenever other users view the trend charts. This makes the vulnerability particularly dangerous in collaborative environments where multiple users interact with Jenkins build monitoring interfaces. The stored nature of the vulnerability means that the malicious payload remains active even after the initial injection, continuously affecting any user who accesses the affected charts.
Mitigation strategies for this vulnerability require immediate patching of the ECharts API Plugin to version 4.7.0-4 or later, which includes proper input sanitization and output escaping mechanisms. Organizations should also implement additional defensive measures such as restricting user permissions for build creation, monitoring for unusual display name patterns, and implementing content security policies to limit script execution. The vulnerability aligns with ATT&CK technique T1059.001 for command and control through scripting, and T1566 for credential access through social engineering, as attackers can leverage the XSS to harvest user sessions and credentials. Regular security audits of Jenkins plugins and proper input validation across all user-facing interfaces remain essential practices to prevent similar vulnerabilities in the broader Jenkins ecosystem.