CVE-2023-33639
📋 TL;DR
This CVE describes a stack overflow vulnerability in H3C Magic R300 routers via the SetMobileAPInfoById interface at /goform/aspForm. Attackers can exploit this to execute arbitrary code or cause denial of service. Affected users are those running vulnerable H3C Magic R300 routers.
💻 Affected Systems
- H3C Magic R300
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete router compromise, credential theft, and lateral movement into connected networks.
Likely Case
Router crash causing denial of service, potentially requiring physical reset.
If Mitigated
Limited impact if network segmentation isolates the router and regular backups exist.
🎯 Exploit Status
Public exploit details available in referenced research. Exploitation requires sending crafted HTTP POST requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: Yes
Instructions:
1. Check H3C vendor website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable web management interface
allPrevent access to vulnerable endpoint by disabling web management
Access router CLI via SSH/Telnet
Disable HTTP/HTTPS management services in configuration
Network segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to restrict access to router IP on ports 80/443
Allow only trusted IP ranges to access management interface
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the router management interface
- Monitor for unusual HTTP POST requests to /goform/aspForm with SetMobileAPInfoById parameter
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface or SSH. If version is R300-2100MV100R004, system is vulnerable.Check Version:
curl -s http://router-ip/ | grep -i version OR ssh admin@router-ip 'show version'Verify Fix Applied:
Verify firmware version has changed from R300-2100MV100R004 to a newer version.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/aspForm with SetMobileAPInfoById parameter
- Router crash/reboot logs
- Unusual process creation
Network Indicators:
- HTTP traffic to router IP on port 80/443 with POST to /goform/aspForm
- Large payloads in HTTP requests to router
SIEM Query:
source="router_logs" AND (uri="/goform/aspForm" AND method="POST" AND params CONTAINS "SetMobileAPInfoById")