Summary
An extension point in Jenkins allows selectively disabling cross-site request forgery (CSRF) protection for specific URLs. SAML Plugin implements this extension point for the URL that users are redirected to after login.
In Jenkins SAML Plugin 2.0.7 and earlier this implementation is too permissive, allowing attackers to craft URLs that would bypass the CSRF protection of any target URL.\n\nThis vulnerability was originally introduced in Jenkins SAML Plugin 1.1.3.
Jenkins SAML Plugin 2.0.8 restricts which URLs it disables cross-site request forgery (CSRF) protection for to the one URL that needs it.
Impact
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
CVE-2021-21678 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.0.8); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-21678? CVE-2021-21678 is a high-severity cross-site request forgery (CSRF) vulnerability in org.jenkins-ci.plugins:saml (maven), affecting versions <= 2.0.7. It is fixed in 2.0.8. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- How severe is CVE-2021-21678? CVE-2021-21678 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.jenkins-ci.plugins:saml are affected by CVE-2021-21678? org.jenkins-ci.plugins:saml (maven) versions <= 2.0.7 is affected.
- Is there a fix for CVE-2021-21678? Yes. CVE-2021-21678 is fixed in 2.0.8. Upgrade to this version or later.
- Is CVE-2021-21678 exploitable, and should I be worried? Whether CVE-2021-21678 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2021-21678 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2021-21678? Upgrade
org.jenkins-ci.plugins:samlto 2.0.8 or later.