CVE-2025-44838
📋 TL;DR
This CVE describes a command injection vulnerability in TOTOLINK CP900 routers that allows attackers to execute arbitrary system commands through the FileName parameter in the setUploadUserData function. Attackers can exploit this to gain unauthorized access, modify device configurations, or launch further attacks. Only TOTOLINK CP900 routers running the specific vulnerable firmware version are affected.
💻 Affected Systems
- TOTOLINK CPE CP900
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, pivot to internal networks, intercept traffic, or use the device as part of a botnet.
Likely Case
Unauthorized access to router configuration, potential credential theft, and limited command execution leading to service disruption.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation attempts from reaching the vulnerable interface.
🎯 Exploit Status
The GitHub repository contains proof-of-concept code demonstrating exploitation. Authentication to the web interface is required, but default credentials may be used.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
Check TOTOLINK's official website for firmware updates. If available, download the latest firmware and upload it through the router's web interface under System Tools > Firmware Upgrade.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the vulnerable web interface by disabling remote management features.
Access router web interface > Advanced > System Tools > Remote Management > Disable
Change Default Credentials
allUse strong, unique credentials to prevent unauthorized access to the management interface.
Access router web interface > Advanced > System Tools > Password > Set strong password
🧯 If You Can't Patch
- Segment affected routers on isolated network segments with strict firewall rules preventing inbound access to management interfaces.
- Implement network monitoring and intrusion detection to alert on command injection attempts targeting the setUploadUserData endpoint.
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface: Advanced > Status > Device Info. Look for version V6.3c.1144_B20190715.Check Version:
curl -s http://router-ip/cgi-bin/status.cgi | grep FirmwareVerify Fix Applied:
After updating firmware, verify the version no longer matches the vulnerable version and test the setUploadUserData function with controlled payloads.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/setUploadUserData.cgi containing shell metacharacters in FileName parameter
- Multiple failed authentication attempts followed by successful login
Network Indicators:
- HTTP requests containing command injection payloads (semicolons, pipes, backticks) in POST parameters
- Outbound connections from router to unexpected external IPs
SIEM Query:
source="router-logs" AND uri_path="/cgi-bin/setUploadUserData.cgi" AND (param="FileName" AND value MATCHES "[;|`$()]+")