CVE-2023-33641
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on H3C Magic R300 routers via a stack overflow in the AddMacList interface. Attackers can exploit this by sending specially crafted requests to the /goform/aspForm endpoint. Only users of H3C Magic R300 version R300-2100MV100R004 are affected.
💻 Affected Systems
- H3C Magic R300
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, and lateral movement to connected devices.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a botnet node.
If Mitigated
Denial of service or temporary disruption if exploit attempts are blocked but successful execution is prevented.
🎯 Exploit Status
Public proof-of-concept exists showing exploitation details. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
1. Check H3C official website for firmware updates
2. If update available, download and install via router web interface
3. No specific patch version information is publicly available
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router management interface
Access router settings → Security → Disable remote management/administration
Restrict management interface access
allLimit which IP addresses can access the router management interface
Access router settings → Firewall → Add rule to restrict management interface to trusted IPs only
🧯 If You Can't Patch
- Segment network to isolate vulnerable routers from critical systems
- Implement network monitoring for exploit attempts targeting /goform/aspForm endpoint
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface: Login → System Tools → Firmware Upgrade → Current VersionCheck Version:
No CLI command available - check via web interface onlyVerify Fix Applied:
Verify firmware version is no longer R300-2100MV100R004 after update📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/aspForm with AddMacList parameter
- Unusual traffic patterns from router management interface
Network Indicators:
- HTTP POST requests to /goform/aspForm with large AddMacList payloads
- Traffic from router to unexpected external IPs
SIEM Query:
http.url:"/goform/aspForm" AND http.method:POST AND http.request_body:"AddMacList"