CVE-2023-33631
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on H3C Magic R300 routers via a stack overflow in the DelSTList interface. Attackers can exploit this by sending specially crafted requests to the /goform/aspForm endpoint. Only users of H3C Magic R300 routers running the specific vulnerable firmware version 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, credential theft, and use as pivot point for internal network attacks.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or launch attacks against internal devices.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Exploit details and proof-of-concept are publicly available. The vulnerability requires no authentication to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Check H3C official website for firmware updates. If update available: 1. Download latest firmware from H3C support portal. 2. Access router admin interface. 3. Navigate to firmware upgrade section. 4. Upload and apply new firmware. 5. Reboot router.
🔧 Temporary Workarounds
Disable WAN Management
allPrevent external access to router management interface
Network Segmentation
allIsolate router on separate VLAN with restricted access
🧯 If You Can't Patch
- Replace vulnerable device with supported model
- Implement strict firewall rules blocking all external access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under System Status or About pageCheck Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version has changed from R300-2100MV100R004 to newer version📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/aspForm with abnormal parameter lengths
- System crash or reboot logs
Network Indicators:
- Unusual traffic patterns to router management interface
- POST requests to /goform/aspForm from external IPs
SIEM Query:
source="router-logs" AND (uri="/goform/aspForm" AND method="POST" AND bytes>1000)