🛡️ CVE-2021-21609 — jenkins

🟡 CVSS 5.0 — Medium ✅ No Known Exploit OSV
5.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Missing permission check for paths with specific prefix in Jenkins

Jenkins includes a static list of URLs that are always accessible even without Overall/Read permission, such as the login form. These URLs are excluded from an otherwise universal permission check.

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not correctly compare requested URLs with that list.

This allows attackers without Overall/Read permission to access plugin-provided URLs with any of the following prefixes if no other permissions are required:

  • accessDenied
  • error
  • instance-identity
  • login
  • logout
  • oops
  • securityRealm
  • signup
  • tcpSlaveAgentListener

For example, a plugin contributing the path loginFoo/ would have URLs in that space accessible without the default Overall/Read permission check.

The Jenkins security team is not aware of any affected plugins as of the publication of this advisory.

The comparison of requested URLs with the list of always accessible URLs has been fixed to only allow access to the specific listed URLs in Jenkins 2.275, LTS 2.263.2.

In case this change causes problems, additional paths can be made accessible without Overall/Read permissions: The [Java system property](https://www.jenkins.io/doc/book/managing/system-properties/) jenkins.model.Jenkins.additionalReadablePaths is a comma-separated list of additional path prefixes to allow access to.

Affected software

CVE-2021-21609 is recorded against 2 packages.

  • jenkins
  • org.jenkins-ci.main:jenkins-core (from 2.264 up to 2.275)

Timeline and source

Published on 6 March 2024 and last revised on 3 April 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

www.jenkins.io (Web)
nvd.nist.gov (Web)

Details

Severity MEDIUM
CVSS Score 5.0
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2024-03-06
Updated 2026-08-12
Modified 2025-04-03
Fix URL N/A

Affected Packages

Software From version Fixed in
jenkins — —
org.jenkins-ci.main:jenkins-core 2.264 2.275

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