CVE-2023-50766
📋 TL;DR
This CSRF vulnerability in Jenkins Nexus Platform Plugin allows attackers to trick authenticated users into making unintended HTTP requests to attacker-controlled URLs and parse the responses as XML. Attackers could potentially access internal systems or exfiltrate data. Affects Jenkins instances with the vulnerable plugin installed.
💻 Affected Systems
- Jenkins Nexus Platform Plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could make authenticated requests to internal systems, potentially accessing sensitive data or performing actions on behalf of authenticated users, leading to data exfiltration or system compromise.
Likely Case
Attackers could redirect authenticated users to malicious sites, parse responses as XML to extract information, or perform limited actions within the Jenkins environment.
If Mitigated
With proper CSRF protections and network segmentation, impact is limited to unsuccessful attack attempts or contained within isolated network segments.
🎯 Exploit Status
Exploitation requires tricking an authenticated user into visiting a malicious page. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.18.0-04 or later
Vendor Advisory: https://www.jenkins.io/security/advisory/2023-12-13/#SECURITY-3204
Restart Required: Yes
Instructions:
1. Update Jenkins Nexus Platform Plugin to version 3.18.0-04 or later via Jenkins Plugin Manager. 2. Restart Jenkins after plugin update. 3. Verify the plugin version in Jenkins plugin management interface.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily disable the Nexus Platform Plugin if immediate patching isn't possible
Navigate to Jenkins > Manage Jenkins > Manage Plugins > Installed tab > Find 'Nexus Platform Plugin' > Click 'Disable'
Implement CSRF protection headers
allAdd CSRF protection headers to Jenkins responses
Configure Jenkins with CSRF protection enabled in 'Configure Global Security' settings
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Jenkins from sensitive internal systems
- Use web application firewalls (WAF) with CSRF protection rules
🔍 How to Verify
Check if Vulnerable:
Check installed plugin version in Jenkins: Manage Jenkins > Manage Plugins > Installed tab > Find 'Nexus Platform Plugin' and check versionCheck Version:
curl -s http://jenkins-host/pluginManager/api/json?depth=1 | grep -o '"shortName":"nexus-platform-plugin","version":"[^"]*"'Verify Fix Applied:
Verify plugin version is 3.18.0-04 or later in Jenkins plugin management interface📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to external URLs from Jenkins
- XML parsing errors or unusual XML responses in logs
- CSRF token validation failures
Network Indicators:
- Outbound HTTP requests from Jenkins to unusual external domains
- XML data being sent to unexpected destinations
SIEM Query:
source="jenkins.log" AND ("nexus-platform-plugin" OR "CSRF" OR "XML parsing")