CVE-2026-3701
📋 TL;DR
A remote buffer overflow vulnerability in H3C Magic B1 routers allows attackers to execute arbitrary code by manipulating the param argument in the Edit_BasicSSID_5G function. This affects H3C Magic B1 routers up to version 100R004. The vulnerability is remotely exploitable and public exploit code exists.
💻 Affected Systems
- H3C Magic B1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise leading to persistent backdoor installation, credential theft, and use as pivot point for internal network attacks.
Likely Case
Remote code execution allowing attacker to modify router settings, intercept traffic, or launch attacks against internal devices.
If Mitigated
Limited impact if device is behind firewall with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code exists on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
No official patch available. Consider replacing affected devices with supported alternatives or implementing strict network controls.
🔧 Temporary Workarounds
Disable remote management
allDisable web management interface access from WAN/Internet
Access router admin interface > Security > Remote Management > Disable
Network segmentation
allPlace router on isolated network segment with strict firewall rules
🧯 If You Can't Patch
- Replace affected H3C Magic B1 routers with supported, patched alternatives
- Implement strict network access controls: block all inbound traffic to router management interface from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface: System > Device Information > Software VersionCheck Version:
Check via web interface or SSH if enabled: show versionVerify Fix Applied:
Verify firmware version is above 100R004 (if patch becomes available)📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/aspForm with Edit_BasicSSID_5G parameter
- Multiple failed buffer overflow attempts
- Unexpected configuration changes
Network Indicators:
- Exploit traffic patterns to router management interface
- Unusual outbound connections from router
SIEM Query:
source_ip="router_ip" AND (url_path="/goform/aspForm" AND param="Edit_BasicSSID_5G")