CVE-2022-30920
📋 TL;DR
This CVE describes a stack overflow vulnerability in H3C Magic R100 routers via the Edit_BasicSSID parameter at /goform/aspForm. Attackers can exploit this to execute arbitrary code or cause denial of service. Affected users are those running vulnerable firmware versions of this specific router model.
💻 Affected Systems
- H3C Magic R100
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and persistent backdoor installation.
Likely Case
Router crash causing denial of service, potentially requiring physical reset or firmware reflash.
If Mitigated
Limited impact if device is behind firewall with restricted web interface access.
🎯 Exploit Status
Public GitHub repository contains proof-of-concept code. Exploitation appears straightforward via HTTP POST request.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found in provided references
Restart Required: Yes
Instructions:
1. Check H3C official website for firmware updates
2. Download latest firmware for Magic R100
3. Access router admin interface
4. Navigate to firmware upgrade section
5. Upload and apply new firmware
6. Reboot router after update
🔧 Temporary Workarounds
Disable Web Interface Access
linuxBlock external access to router web administration interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Change Default Credentials
allEnsure strong, unique admin credentials are set
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Implement network segmentation to limit potential lateral movement
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface or SSH if available. Version should be R100V100R005 or potentially other vulnerable versions.Check Version:
curl -s http://router-ip/status.cgi | grep firmware || ssh admin@router-ip 'cat /etc/version'Verify Fix Applied:
Verify firmware version has been updated to a version later than R100V100R005. Test the vulnerable endpoint with safe payloads.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/aspForm with large Edit_BasicSSID parameter
- Router crash/reboot logs
- Memory corruption errors in system logs
Network Indicators:
- HTTP POST requests to router IP on port 80/443 with oversized parameters
- Unusual outbound connections from router after exploitation
SIEM Query:
source="router_logs" AND (uri="/goform/aspForm" AND method="POST" AND param_size>1000)