CVE-2022-24259
📋 TL;DR
CVE-2022-24259 is an authentication bypass vulnerability in Voipmonitor GUI's cdr.php component that allows unauthenticated attackers to escalate privileges via crafted requests. This affects all Voipmonitor GUI installations before version 24.96. Attackers can gain administrative access without valid credentials.
💻 Affected Systems
- Voipmonitor GUI
📦 What is this software?
Voipmonitor by Voipmonitor
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise - attackers gain administrative access to the Voipmonitor GUI, potentially accessing sensitive call data records, modifying configurations, and using the system as a foothold for further network attacks.
Likely Case
Unauthorized administrative access to the Voipmonitor GUI, allowing attackers to view sensitive call metadata, modify monitoring configurations, and potentially access other integrated systems.
If Mitigated
Limited impact if the system is isolated, has strict network controls, and the GUI is not internet-facing. However, the authentication bypass remains a serious vulnerability.
🎯 Exploit Status
The vulnerability requires sending a crafted HTTP request to the cdr.php endpoint. Public technical details and proof-of-concept information are available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 24.96 and later
Vendor Advisory: https://www.voipmonitor.org/changelog-gui?major=5
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download Voipmonitor GUI version 24.96 or later from the official website. 3. Stop the Voipmonitor service. 4. Install the updated version. 5. Restart the service. 6. Verify the version is 24.96 or higher.
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict network access to the Voipmonitor GUI to only trusted IP addresses or internal networks
# Example iptables rule: iptables -A INPUT -p tcp --dport [GUI_PORT] -s [TRUSTED_IP] -j ACCEPT
# Then: iptables -A INPUT -p tcp --dport [GUI_PORT] -j DROP
Web Server Authentication
allImplement additional authentication layer at the web server level (e.g., HTTP basic auth, IP-based restrictions)
# Apache example: AuthType Basic
# AuthName "Restricted Access"
# AuthUserFile /path/to/.htpasswd
# Require valid-user
🧯 If You Can't Patch
- Isolate the Voipmonitor GUI on a separate network segment with strict firewall rules
- Implement network-based intrusion detection to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if the Voipmonitor GUI version is below 24.96. Attempt to access administrative functions without authentication via the cdr.php endpoint.Check Version:
Check the web interface footer or configuration files for version information, or use: grep -i version /path/to/voipmonitor/config/filesVerify Fix Applied:
After patching, verify the version is 24.96 or higher and test that unauthenticated access to administrative functions via cdr.php is no longer possible.📡 Detection & Monitoring
Log Indicators:
- Unauthenticated access to cdr.php with administrative parameters
- Multiple failed authentication attempts followed by successful administrative actions
- Unusual administrative activity from non-admin IP addresses
Network Indicators:
- HTTP requests to /cdr.php with administrative parameters from unauthenticated sources
- Unusual traffic patterns to the Voipmonitor GUI port
SIEM Query:
source="voipmonitor" AND (uri="/cdr.php" AND (param="admin" OR param="privileged")) AND auth_status="failed"