CVE-2023-34930
📋 TL;DR
A stack overflow vulnerability in the EditMacList function of H3C Magic B1STV100R012 routers allows attackers to cause Denial of Service (DoS) via crafted POST requests. This affects H3C Magic B1STV100R012 routers, potentially disrupting network connectivity for users.
💻 Affected Systems
- H3C Magic B1STV100R012
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reboot, extended network downtime, and potential for remote code execution if stack overflow can be controlled.
Likely Case
Router becomes unresponsive, requiring reboot to restore functionality, causing temporary network disruption.
If Mitigated
Minimal impact with proper network segmentation and monitoring; device may still crash but can be quickly restored.
🎯 Exploit Status
Proof of concept available on GitHub demonstrates simple POST request exploitation. No authentication required based on available information.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not found in provided references
Instructions:
No official patch available. Check H3C vendor website for firmware updates addressing CVE-2023-34930.
🔧 Temporary Workarounds
Disable web management interface
allDisable the router's web management interface to prevent exploitation via POST requests
Access router CLI via SSH/Telnet
Navigate to web management settings
Disable HTTP/HTTPS management interface
Restrict management interface access
allLimit access to router management interface to trusted IP addresses only
Configure firewall rules to restrict access to router management IP:port
Allow only specific source IPs to access management interface
🧯 If You Can't Patch
- Segment affected routers on isolated network segments
- Implement network monitoring for abnormal POST requests to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface or CLI. If running V100R012, assume vulnerable until patched.Check Version:
Login to router web interface or use CLI command 'show version' to check firmware versionVerify Fix Applied:
Verify firmware version has been updated to a version not listed as vulnerable. Test with controlled exploit attempt if possible.📡 Detection & Monitoring
Log Indicators:
- Multiple failed POST requests to EditMacList endpoint
- Router crash/reboot logs
- Unusual traffic patterns to router management interface
Network Indicators:
- Abnormal POST requests to router management interface
- Sudden loss of connectivity from affected router
SIEM Query:
source_ip="router_management_interface" AND http_method="POST" AND uri="*EditMacList*" AND size>threshold