CVE-2021-21607 Excessive memory allocation in graph URLs leads to denial of service in Jenkins

What is CVE-2021-21607?

CVE-2021-21607 is a medium-severity denial of service vulnerability in Jenkins Jenkins, published on 13 Jan 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not limit sizes provided as query parameters to graph-rendering URLs, allowing attackers to request crafted URLs that use all available memory in Jenkins, potentially leading to out of memory errors.

Weakness: CWE-770

Which versions are affected by CVE-2021-21607?

5 open source packages ship an affected version, including org.jenkins-ci.main:jenkins-core and jenkins. It affects 1 product.

Products include Jenkins Jenkins.

How do I fix CVE-2021-21607?

Upgrade org.jenkins-ci.main:jenkins-core to a fixed version for your release line: 2.263.2 or 2.275.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-21607 being exploited?

There is no known exploitation of CVE-2021-21607 in the wild and no public exploit code.

Other vulnerabilities in Jenkins Jenkins

• CVE-2024-23897 Jenkins Command Line Interface (CLI) Path Traversal Exploited Critical 9.8
• CVE-2018-1000861 Jenkins Stapler Web Framework Deserialization of Untrusted Data Exploited Critical 9.8
• CVE-2017-1000353 Jenkins Remote Code Execution Exploited Critical 9.8
• CVE-2015-5317 Jenkins User Interface (UI) Information Disclosure Exploited High 7.5
• CVE-2021-21690 Multiple vulnerabilities allow bypassing path filtering of agent-to-controller access control in Jenkins Critical 9.8

All Jenkins Jenkins vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-jenkins-2021-21607, GHSA-cxqw-vjcr-gp5g.