CVE-2024-23828
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary commands on Nginx-UI servers via CRLF injection when modifying test_config_cmd or start_cmd parameters. It affects all Nginx-UI installations with versions before 2.0.0.beta.12. The vulnerability stems from an incomplete fix for previous command injection issues.
💻 Affected Systems
- Nginx-UI
📦 What is this software?
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
Nginx Ui by Nginxui
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining root privileges, installing persistent backdoors, and pivoting to other systems in the network.
Likely Case
Unauthorized command execution leading to data theft, service disruption, or deployment of cryptocurrency miners.
If Mitigated
Limited impact due to network segmentation and restricted user permissions, potentially only affecting the Nginx-UI service.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained. The CRLF injection technique is well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.0.beta.12
Vendor Advisory: https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-qcjq-7f7v-pvc8
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Stop Nginx-UI service. 3. Update to version 2.0.0.beta.12 or later. 4. Restart Nginx-UI service. 5. Verify functionality.
🔧 Temporary Workarounds
Restrict Access
linuxLimit network access to Nginx-UI interface using firewall rules
iptables -A INPUT -p tcp --dport [nginx-ui-port] -s [trusted-ip] -j ACCEPT
iptables -A INPUT -p tcp --dport [nginx-ui-port] -j DROP
Disable Vulnerable Features
linuxRemove or restrict access to configuration modification features
chmod 000 /path/to/nginx-ui/config/modules
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Nginx-UI from critical systems
- Enforce strong authentication policies and monitor for suspicious login attempts
🔍 How to Verify
Check if Vulnerable:
Check Nginx-UI version via web interface or configuration files. Versions before 2.0.0.beta.12 are vulnerable.Check Version:
grep version /path/to/nginx-ui/package.json or check web interface dashboardVerify Fix Applied:
Confirm version is 2.0.0.beta.12 or later and test configuration modification functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns in system logs
- Multiple failed authentication attempts followed by configuration changes
- CRLF sequences in configuration modification requests
Network Indicators:
- Unexpected outbound connections from Nginx-UI server
- Traffic to known malicious IPs or domains
SIEM Query:
source="nginx-ui" AND (event="config_modification" OR event="command_execution") | stats count by src_ip, user