CVE-2022-30922
📋 TL;DR
This CVE describes a critical stack overflow vulnerability in H3C Magic R100 routers that allows remote attackers to execute arbitrary code via a specially crafted request to the EditWlanMacList parameter. The vulnerability affects H3C Magic R100 routers running firmware version V100R005. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- H3C Magic R100
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full root access to the router, enabling them to intercept all network traffic, install persistent malware, pivot to internal networks, or brick the device.
Likely Case
Remote attacker executes arbitrary code with root privileges, potentially creating a botnet node, intercepting credentials, or modifying router configuration.
If Mitigated
With proper network segmentation and firewall rules blocking external access to router management interfaces, impact is limited to internal attackers only.
🎯 Exploit Status
Public proof-of-concept code exists in GitHub repositories. The vulnerability requires sending a crafted HTTP POST request to /goform/aspForm with malicious EditWlanMacList parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
Check H3C official website for firmware updates. If available, download latest firmware and apply through router web interface under System Tools > Firmware Upgrade.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Access router web interface > Security > Remote Management > Disable
Restrict management interface access
linuxUse firewall rules to limit access to router management IP/port
iptables -A INPUT -p tcp --dport 80 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Segment router management interface to isolated VLAN with strict access controls
- Implement network monitoring for unusual traffic to router management interface (port 80/tcp)
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface (Status > Device Info) or via command: curl -s http://router_ip/ | grep -i firmwareCheck Version:
curl -s http://router_ip/ | grep -o 'V100R005' || echo 'Version not found'Verify Fix Applied:
Verify firmware version is no longer V100R005. Test if /goform/aspForm endpoint still accepts EditWlanMacList parameter with malformed data.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/aspForm
- Large EditWlanMacList parameter values in web logs
- Router crash/restart events
Network Indicators:
- HTTP POST requests to router_ip/goform/aspForm with large payloads
- Unusual outbound connections from router after exploitation
SIEM Query:
source="router_logs" AND uri="/goform/aspForm" AND (param="EditWlanMacList" OR bytes>1024)