CVE-2021-21671: Session fixation vulnerability in Jenkins
7.5
CVSS Score
3.1
Basic Information
CVE ID
GHSA ID
EPSS Score
0.64327%
CWE
Published
5/24/2022
Updated
12/6/2023
KEV Status
No
Technology
Java
Technical Details
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Package Name | Ecosystem | Vulnerable Versions | First Patched Version |
---|---|---|---|
org.jenkins-ci.main:jenkins-core | maven | >= 2.292, <= 2.299 | 2.300 |
org.jenkins-ci.main:jenkins-core | maven | <= 2.289.1 | 2.289.2 |
Vulnerability Intelligence
Miggo AI
Root Cause Analysis
The vulnerability stems from missing session invalidation during authentication. The commit diff shows the fix added session invalidation logic in AuthenticationProcessingFilter2.successfulAuthentication()
when sessionFixationProtectionMode=2. The original code (before patch) lacked this critical security measure, making it possible to maintain a session across login events. The test case SecurityRealmSecurity2371Test
explicitly verifies session ID changes post-login, confirming this was the vulnerable entry point.