CVE-2021-21607

Jenkins renders several different graphs for features like agent and label usage statistics, memory usage, or various plugin-provided statistics.

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not limit the graph size provided as query parameters.

This allows attackers to request or to have legitimate Jenkins users request crafted URLs that rapidly use all available memory in Jenkins, potentially leading to out of memory errors.

Jenkins 2.275, LTS 2.263.2 limits the maximum size of graphs to an area of 10 million pixels. If a larger size is requested, the default size for the graph will be rendered instead.

This threshold can be configured by setting the Java system property hudson.util.Graph.maxArea to a different number on startup.

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

CVE-2021-21607 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. 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 (2.263.2, 2.275); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2021-21607? CVE-2021-21607 is a medium-severity allocation of resources without limits or throttling vulnerability in org.jenkins-ci.main:jenkins-core (maven), affecting versions <= 2.263.1. It is fixed in 2.263.2, 2.275. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
2. How severe is CVE-2021-21607? CVE-2021-21607 has a CVSS score of 6.5 (Medium). 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.
3. Which versions of org.jenkins-ci.main:jenkins-core are affected by CVE-2021-21607? org.jenkins-ci.main:jenkins-core (maven) versions <= 2.263.1 is affected.
4. Is there a fix for CVE-2021-21607? Yes. CVE-2021-21607 is fixed in 2.263.2, 2.275. Upgrade to this version or later.
5. Is CVE-2021-21607 exploitable, and should I be worried? Whether CVE-2021-21607 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
6. What actually determines whether CVE-2021-21607 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.
7. How do I fix CVE-2021-21607?
   • Upgrade org.jenkins-ci.main:jenkins-core to 2.263.2 or later
   • Upgrade org.jenkins-ci.main:jenkins-core to 2.275 or later

Other vulnerabilities in org.jenkins-ci.main:jenkins-core