CVE-2020-29311
📋 TL;DR
CVE-2020-29311 is a critical remote command execution vulnerability in Ubilling v1.0.9 that allows attackers to execute arbitrary commands as the root user by injecting malicious commands into configuration files. This affects all Ubilling v1.0.9 installations with default configurations. Attackers can achieve complete system compromise through this vulnerability.
💻 Affected Systems
- Ubilling
📦 What is this software?
Ubilling by Ubilling
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with root privileges, allowing installation of persistent backdoors, data exfiltration, and lateral movement across the network.
Likely Case
Remote attackers gain root shell access to the Ubilling server, enabling them to steal sensitive billing data, modify system configurations, and use the server as a pivot point.
If Mitigated
With proper network segmentation and strict access controls, impact could be limited to the Ubilling application server only.
🎯 Exploit Status
Multiple public proof-of-concept exploits are available. The attack requires minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.0.10 or later
Vendor Advisory: https://github.com/nightflyza/Ubilling-NG/releases
Restart Required: Yes
Instructions:
1. Backup current installation and data. 2. Download latest version from official repository. 3. Replace vulnerable files with patched version. 4. Restart web server and Ubilling services.
🔧 Temporary Workarounds
Configuration File Hardening
linuxRestrict write permissions to configuration files and implement input validation
chmod 644 /path/to/ubilling/config/*
chown root:root /path/to/ubilling/config/*
Network Access Restriction
linuxLimit access to Ubilling web interface to trusted IP addresses only
iptables -A INPUT -p tcp --dport 80 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Immediately isolate the Ubilling server from internet access and restrict internal network access
- Implement strict monitoring and alerting for any configuration file modifications or unusual root activity
🔍 How to Verify
Check if Vulnerable:
Check if Ubilling version is exactly 1.0.9 by examining version files or web interface footerCheck Version:
grep -r 'version' /path/to/ubilling/ | grep -i '1.0.9'Verify Fix Applied:
Verify version is 1.0.10 or later and test configuration file injection attempts are properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual configuration file modifications
- Commands executed from web interface with root privileges
- Suspicious POST requests to configuration endpoints
Network Indicators:
- Unusual outbound connections from Ubilling server
- SSH or reverse shell connections originating from web server process
SIEM Query:
source="ubilling.log" AND ("config" AND "modif" OR "root" AND "command")🔗 References
- https://drive.google.com/file/d/1iLMFSbY8x1CXIf0uFntovY6yZ7N24dQA/view?usp=sharing
- https://drive.google.com/file/d/1smOjvenPB-nE0PyIxnfujCT4KcxxkeWV/view?usp=sharing
- https://gist.github.com/mhaskar/bfa9c2c799fca6697bcc6a213d08cb3e
- https://drive.google.com/file/d/1iLMFSbY8x1CXIf0uFntovY6yZ7N24dQA/view?usp=sharing
- https://drive.google.com/file/d/1smOjvenPB-nE0PyIxnfujCT4KcxxkeWV/view?usp=sharing
- https://gist.github.com/mhaskar/bfa9c2c799fca6697bcc6a213d08cb3e
