CVE-2025-67188
📋 TL;DR
This buffer overflow vulnerability in TOTOLINK A950RG routers allows remote attackers to execute arbitrary code by sending specially crafted requests to the setRadvdCfg interface. Attackers can potentially take full control of affected routers. Users of TOTOLINK A950RG routers with vulnerable firmware versions are affected.
💻 Affected Systems
- TOTOLINK A950RG
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, and lateral movement to other network devices.
Likely Case
Router compromise allowing traffic interception, DNS hijacking, credential theft, and botnet recruitment.
If Mitigated
Limited impact if network segmentation isolates routers and strict access controls prevent exploitation attempts.
🎯 Exploit Status
Public GitHub repository contains technical details and likely exploit code. Buffer overflow with user-controlled parameter suggests straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: Yes
Instructions:
1. Check TOTOLINK official website for firmware updates. 2. Download latest firmware for A950RG. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable IPv6 functionality
allDisable IPv6 routing advertisement daemon to remove vulnerable interface
Access router admin interface
Navigate to IPv6 settings
Disable radvd/RA service
Network segmentation and access control
allIsolate router management interface from untrusted networks
Configure firewall rules to restrict access to router admin interface
Use VLANs to separate management traffic
🧯 If You Can't Patch
- Segment router on isolated network with strict inbound/outbound firewall rules
- Implement network monitoring for exploitation attempts and anomalous router behavior
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface. If version is V4.1.2cu.5204_B20210112 or similar, device is vulnerable.Check Version:
Login to router admin interface and check System Status or Firmware Information pageVerify Fix Applied:
Verify firmware version has been updated to a version later than V4.1.2cu.5204_B20210112. Test IPv6 functionality remains operational if workaround was applied.📡 Detection & Monitoring
Log Indicators:
- Unusual requests to /lib/cste_modules/ipv6.so
- Multiple failed authentication attempts followed by setRadvdCfg requests
- Router crash/reboot logs
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Traffic patterns indicating router compromise
SIEM Query:
source="router_logs" AND (uri="/lib/cste_modules/ipv6.so" OR process="radvd" OR message="buffer overflow")