CVE-2020-2276
📋 TL;DR
CVE-2020-2276 is a command injection vulnerability in Jenkins Selection tasks Plugin that allows attackers with Job/Configure permission to execute arbitrary system commands on the Jenkins controller. This affects Jenkins instances running the vulnerable plugin version, potentially leading to full system compromise.
💻 Affected Systems
- Jenkins Selection tasks Plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the Jenkins controller with execution of arbitrary commands as the Jenkins process user, potentially leading to lateral movement, data exfiltration, or ransomware deployment.
Likely Case
Attackers with Job/Configure permission execute commands to steal credentials, install backdoors, or disrupt Jenkins operations.
If Mitigated
Limited impact if proper access controls restrict Job/Configure permissions to trusted users only.
🎯 Exploit Status
Exploitation requires Job/Configure permission. Public proof-of-concept exists in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to Jenkins Selection tasks Plugin 1.1 or later
Vendor Advisory: https://www.jenkins.io/security/advisory/2020-09-16/#SECURITY-1967
Restart Required: Yes
Instructions:
1. Navigate to Jenkins Manage Jenkins > Manage Plugins. 2. Go to Available tab. 3. Search for 'Selection tasks Plugin'. 4. Install version 1.1 or later. 5. Restart Jenkins.
🔧 Temporary Workarounds
Remove vulnerable plugin
allUninstall the Selection tasks Plugin if not required
Navigate to Manage Jenkins > Manage Plugins > Installed tab, find 'Selection tasks Plugin', click Uninstall
Restrict Job/Configure permissions
allLimit Job/Configure permissions to only necessary users
Configure Jenkins security matrix to restrict Job/Configure permissions
🧯 If You Can't Patch
- Immediately restrict Job/Configure permissions to minimal trusted users only
- Monitor Jenkins logs for suspicious command execution patterns
🔍 How to Verify
Check if Vulnerable:
Check installed plugin version in Manage Jenkins > Manage Plugins > Installed tab. If Selection tasks Plugin version is 1.0 or earlier, you are vulnerable.Check Version:
Check Jenkins plugin manager or view $JENKINS_HOME/plugins/selection-tasks-plugin/META-INF/MANIFEST.MFVerify Fix Applied:
Verify Selection tasks Plugin version is 1.1 or later in Manage Jenkins > Manage Plugins > Installed tab.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in Jenkins logs
- Selection tasks Plugin related errors with command parameters
Network Indicators:
- Unexpected outbound connections from Jenkins controller
SIEM Query:
source="jenkins.log" AND "selection-tasks" AND ("exec" OR "cmd" OR "command")