CVE-2025-5156
📋 TL;DR
A critical buffer overflow vulnerability in H3C GR-5400AX routers allows remote attackers to execute arbitrary code by manipulating the 'param' argument in the EditWlanMacList function. This affects all versions up to 100R008, potentially compromising the entire device and network. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- H3C GR-5400AX
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to other systems, and data exfiltration.
Likely Case
Remote code execution resulting in device compromise, network disruption, and potential credential theft from connected devices.
If Mitigated
Limited impact if device is behind strict firewall rules, but still vulnerable to internal threats or if perimeter is breached.
🎯 Exploit Status
Public exploit code available on GitHub. Attack requires network access to the web interface but no credentials.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
No official patch available. Monitor H3C security advisories for updates. Consider replacing affected devices if no patch becomes available.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected routers in separate VLANs with strict firewall rules limiting access to management interface
Access Control
allRestrict access to router web interface using IP whitelisting and disable remote management if not required
🧯 If You Can't Patch
- Replace affected H3C GR-5400AX routers with patched or alternative devices
- Implement strict network monitoring and intrusion detection for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at System > System Information or via CLI command 'display version'Check Version:
display versionVerify Fix Applied:
Verify firmware version is above 100R008 when/if patch becomes available📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /routing/goform/aspForm with large parameter values
- Multiple failed exploitation attempts with buffer overflow patterns
- System crash or reboot logs
Network Indicators:
- HTTP traffic to router management interface with unusually long parameter strings
- Traffic patterns matching known exploit signatures
SIEM Query:
source_ip="router_ip" AND uri="/routing/goform/aspForm" AND param_length>1000