CVE-2025-27624
📋 TL;DR
This CSRF vulnerability in Jenkins allows attackers to trick authenticated users into toggling the collapsed/expanded status of sidepanel widgets like Build Queue and Build Executor Status. It affects Jenkins 2.499 and earlier, and LTS 2.492.1 and earlier. While it doesn't directly compromise data or systems, it can disrupt user interface functionality.
💻 Affected Systems
- Jenkins
📦 What is this software?
Jenkins by Jenkins
Jenkins by Jenkins
⚠️ Risk & Real-World Impact
Worst Case
An attacker could repeatedly toggle widget states for multiple users, causing persistent UI disruption and potential productivity loss for Jenkins administrators and users.
Likely Case
Temporary UI annoyance where users find their widget states unexpectedly changed, requiring manual correction of their preferred layout.
If Mitigated
Minimal impact with proper CSRF protections enabled and users educated about phishing risks.
🎯 Exploit Status
Exploitation requires the victim to be authenticated to Jenkins and tricked into visiting a malicious webpage. Standard CSRF attack patterns apply.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Jenkins 2.500, Jenkins LTS 2.492.2
Vendor Advisory: https://www.jenkins.io/security/advisory/2025-03-05/#SECURITY-3498
Restart Required: Yes
Instructions:
1. Backup your Jenkins instance and configuration. 2. Download Jenkins 2.500 or Jenkins LTS 2.492.2 from official sources. 3. Stop the Jenkins service. 4. Install the updated version following platform-specific installation procedures. 5. Restart Jenkins service. 6. Verify the update was successful.
🔧 Temporary Workarounds
Enable Strict CSRF Protection
allEnsure Jenkins CSRF protection is enabled and configured with strict settings
Check 'Enable security' in Jenkins Configure Global Security settings
Ensure 'Prevent Cross Site Request Forgery exploits' is checked
User Education
allEducate users about phishing risks and not clicking suspicious links while authenticated
🧯 If You Can't Patch
- Implement network segmentation to restrict Jenkins access to trusted users only
- Deploy web application firewall (WAF) with CSRF protection rules
🔍 How to Verify
Check if Vulnerable:
Check Jenkins version via Manage Jenkins → About Jenkins or via CLI with 'java -jar jenkins.war --version'Check Version:
java -jar jenkins.war --versionVerify Fix Applied:
Verify version is 2.500 or higher (or LTS 2.492.2 or higher) and test that widget toggle actions now include proper CSRF tokens📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /user/[username]/toggleCollapse without corresponding GET requests
- Unusual pattern of widget state change requests from same IP
Network Indicators:
- HTTP POST requests to Jenkins toggleCollapse endpoints without proper Referer headers or CSRF tokens
SIEM Query:
source="jenkins.log" AND "toggleCollapse" AND NOT "X-Jenkins-Crumb"