CVE-2020-13925
📋 TL;DR
CVE-2020-13925 is a critical OS command injection vulnerability in Apache Kylin's REST API that allows remote attackers to execute arbitrary commands on the server. This affects all Apache Kylin versions from 2.3.0 to 3.0.2. Attackers can achieve remote code execution with high privileges on affected systems.
💻 Affected Systems
- Apache Kylin
📦 What is this software?
Kylin by Apache
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining root/administrator access, data exfiltration, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to data theft, service disruption, cryptocurrency mining, or ransomware deployment.
If Mitigated
Limited impact if proper network segmentation, least privilege, and input validation are implemented.
🎯 Exploit Status
Simple command injection via API parameters. Similar to CVE-2020-1956 with different vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.1.0
Vendor Advisory: https://lists.apache.org/thread.html/r021baf9d8d4ae41e8c8332c167c4fa96c91b5086563d9be55d2d7acf@%3Ccommits.kylin.apache.org%3E
Restart Required: Yes
Instructions:
1. Backup current Kylin configuration and data. 2. Download Apache Kylin 3.1.0 from official Apache repository. 3. Stop Kylin service. 4. Replace installation with 3.1.0 version. 5. Restore configuration if needed. 6. Start Kylin service. 7. Verify functionality.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict access to Kylin REST API endpoints using firewall rules or network segmentation.
iptables -A INPUT -p tcp --dport 7070 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 7070 -j DROP
Web Application Firewall
allDeploy WAF with command injection rules to block malicious API requests.
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all API parameters
- Run Kylin with minimal privileges using non-root user accounts
🔍 How to Verify
Check if Vulnerable:
Check Kylin version via web interface or configuration files. Versions 2.3.0-3.0.2 are vulnerable.Check Version:
curl -s http://kylin-server:7070/kylin/api/admin/version | grep versionVerify Fix Applied:
Confirm Kylin version is 3.1.0 or higher using version check command or web interface.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns in system logs
- Suspicious API requests to Kylin endpoints with shell metacharacters
- Unexpected process creation from Kylin service account
Network Indicators:
- Unusual outbound connections from Kylin server
- API requests containing shell commands or special characters
SIEM Query:
source="kylin.log" AND ("cmd.exe" OR "/bin/sh" OR "bash" OR "powershell" OR "|" OR ";" OR "&" OR "$")🔗 References
- https://lists.apache.org/thread.html/r021baf9d8d4ae41e8c8332c167c4fa96c91b5086563d9be55d2d7acf%40%3Ccommits.kylin.apache.org%3E
- https://lists.apache.org/thread.html/r250a867961cfd6e0506240a9c7eaee782d84c6ab0091c7c4bc45f3eb%40%3Cuser.kylin.apache.org%3E
- https://lists.apache.org/thread.html/r021baf9d8d4ae41e8c8332c167c4fa96c91b5086563d9be55d2d7acf%40%3Ccommits.kylin.apache.org%3E
- https://lists.apache.org/thread.html/r250a867961cfd6e0506240a9c7eaee782d84c6ab0091c7c4bc45f3eb%40%3Cuser.kylin.apache.org%3E
