CVE-2025-44840
📋 TL;DR
This CVE describes a command injection vulnerability in TOTOLINK CA600-PoE routers that allows attackers to execute arbitrary commands via the svn parameter in the CloudSrvUserdataVersionCheck function. Attackers can potentially gain full control of affected devices through crafted requests. Organizations using TOTOLINK CA600-PoE routers with vulnerable firmware are affected.
💻 Affected Systems
- TOTOLINK CA600-PoE
📦 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
Remote code execution leading to device takeover, credential theft, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation is properly implemented.
🎯 Exploit Status
The GitHub reference contains detailed exploitation information and proof-of-concept code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
Check TOTOLINK official website for firmware updates. If available, download and apply the latest firmware through the device's web interface.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices in separate VLANs with strict firewall rules to prevent external access.
Access Control
allRestrict access to device management interfaces using firewall rules and only allow from trusted IP addresses.
🧯 If You Can't Patch
- Disable cloud management features if not required
- Implement network monitoring for suspicious outbound connections from the device
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface at System Status > Firmware Version. If version is V5.3c.6665_B20180820, device is vulnerable.Check Version:
Check via web interface or SSH if enabled: cat /proc/versionVerify Fix Applied:
Verify firmware version has been updated to a version newer than V5.3c.6665_B20180820.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Unexpected process creation
- Failed authentication attempts to device management
Network Indicators:
- Suspicious outbound connections from router
- Unexpected traffic patterns
- Connection attempts to the vulnerable endpoint
SIEM Query:
source="router_logs" AND ("CloudSrvUserdataVersionCheck" OR "svn parameter")