CVE-2025-3854
📋 TL;DR
A critical buffer overflow vulnerability in H3C GR-3000AX routers allows attackers to execute arbitrary code or crash the device by sending specially crafted HTTP POST requests to vulnerable form handlers. This affects local network attackers who can reach the router's web interface. The vulnerability is in multiple form processing functions that handle IPv6, WAN mode, and wireless configuration parameters.
💻 Affected Systems
- H3C GR-3000AX
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Device crash causing denial of service, potential information disclosure from memory dumps, and limited code execution for privilege escalation.
If Mitigated
Denial of service from crashes if exploit attempts are blocked, but no code execution due to memory protections.
🎯 Exploit Status
Exploit details are publicly available on GitHub. The vulnerability requires sending crafted HTTP POST requests to specific endpoints, which is straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after V100R006
Vendor Advisory: https://www.h3c.com/cn/Service/Document_Software/Software_Download/Consume_product/
Restart Required: Yes
Instructions:
1. Download the latest firmware from H3C's official website. 2. Log into the router's web interface. 3. Navigate to System Tools > Firmware Upgrade. 4. Upload the new firmware file. 5. Wait for the upgrade to complete and the router to reboot.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the vulnerable HTTP POST handler by turning off the web management interface if not needed.
Configure via CLI: system-view
interface vlan-interface 1
undo ip http enable
undo ip https enable
Restrict Management Access
allLimit access to the management interface to specific trusted IP addresses using ACLs.
Configure via CLI: acl basic 2000
rule permit source 192.168.1.100 0
rule deny source any
interface vlan-interface 1
ip http acl 2000
🧯 If You Can't Patch
- Isolate the router on a dedicated management VLAN with strict access controls
- Implement network segmentation to limit lateral movement if the router is compromised
🔍 How to Verify
Check if Vulnerable:
Check the firmware version via web interface (System Tools > Device Information) or CLI (display version). If version is V100R006 or earlier, the device is vulnerable.Check Version:
display version | include GR-3000AXVerify Fix Applied:
After upgrading, verify the firmware version shows a version higher than V100R006. Test by attempting to send crafted POST requests to /goform/aspForm endpoints and ensure they are rejected or handled safely.📡 Detection & Monitoring
Log Indicators:
- Multiple failed POST requests to /goform/aspForm with unusual parameter lengths
- Device reboot events following POST requests
- Memory allocation errors in system logs
Network Indicators:
- Unusual HTTP POST traffic to router management IP on port 80/443 with large parameter values
- Traffic patterns matching known exploit payloads
SIEM Query:
source_ip="router_ip" AND (url_path="/goform/aspForm" AND http_method="POST" AND content_length>1000)