CVE-2025-3854 Overview
CVE-2025-3854 is a buffer overflow vulnerability in the H3C GR-3000AX wireless router through firmware version V100R006. The flaw resides in the /goform/aspForm endpoint of the HTTP POST Request Handler component. Multiple handler functions are affected, including EnableIpv6, UpdateWanModeMulti, UpdateIpv6Params, EditWlanMacList, and Edit_List_SSID. An attacker on the adjacent network can manipulate the param argument to trigger memory corruption. The exploit has been publicly disclosed, increasing exposure risk for unpatched devices. The weakness is classified under [CWE-119] for improper restriction of operations within the bounds of a memory buffer.
Critical Impact
Authenticated adjacent-network attackers can trigger a buffer overflow in the H3C GR-3000AX router, potentially leading to arbitrary code execution or device compromise.
Affected Products
- H3C GR-3000AX router firmware up to V100R006
- /goform/aspForm HTTP POST Request Handler component
- Handler functions: EnableIpv6, UpdateWanModeMulti, UpdateIpv6Params, EditWlanMacList, Edit_List_SSID
Discovery Timeline
- 2025-04-22 - CVE-2025-3854 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-3854
Vulnerability Analysis
The vulnerability exists in the web management interface of the H3C GR-3000AX router. The /goform/aspForm endpoint dispatches incoming HTTP POST requests to multiple handler functions based on request parameters. Several of these handlers, including EnableIpv6, UpdateWanModeMulti, UpdateIpv6Params, EditWlanMacList, and Edit_List_SSID, process the param argument without adequate bounds checking. When an attacker submits an oversized value, the handler writes past the end of a fixed-size buffer, corrupting adjacent memory. The vendor advisory notes that additional handler functions may exhibit the same defect.
Root Cause
The root cause is improper restriction of memory buffer operations, classified as [CWE-119]. The affected handlers copy attacker-controlled input from the param argument into stack or heap buffers without validating length constraints. This absence of input length validation allows overwriting return addresses, function pointers, or adjacent structures. Similar patterns across five distinct functions suggest a systemic lack of a shared safe-copy routine in the request handling code.
Attack Vector
Exploitation requires network reachability to the router's management interface, typically from within the local network or an adjacent segment. An attacker with low-privilege credentials can send a crafted HTTP POST request to /goform/aspForm targeting one of the vulnerable handlers. The public disclosure of the exploit lowers the technical barrier for adversaries seeking to compromise affected devices. Successful exploitation may result in denial of service or arbitrary code execution on the router, providing a foothold for lateral movement into the internal network.
Detailed technical documentation and proof-of-concept artifacts are available in the GitHub Repository Documentation and VulDB #305778.
Detection Methods for CVE-2025-3854
Indicators of Compromise
- Unusual HTTP POST requests to /goform/aspForm containing oversized param values.
- Router crashes, unexpected reboots, or management interface unavailability following inbound requests to affected handlers.
- Unauthorized configuration changes affecting IPv6, WAN mode, WLAN MAC filtering, or SSID lists.
Detection Strategies
- Inspect network traffic to router management interfaces for POST requests targeting EnableIpv6, UpdateWanModeMulti, UpdateIpv6Params, EditWlanMacList, and Edit_List_SSID functions.
- Deploy network intrusion detection signatures that flag anomalously large payloads on the param parameter of /goform/aspForm.
- Correlate router log anomalies with authenticated management sessions originating from unexpected internal hosts.
Monitoring Recommendations
- Enable syslog forwarding from the H3C router to a centralized logging platform and alert on repeated authentication or handler errors.
- Baseline normal administrative traffic patterns and alert on deviations in POST request size to the web management interface.
- Monitor for lateral movement or reconnaissance activity originating from the router's IP address, which may indicate post-exploitation.
How to Mitigate CVE-2025-3854
Immediate Actions Required
- Restrict access to the router's web management interface to trusted administrative hosts only, using firewall rules or management VLANs.
- Change default and reused administrative credentials to reduce the risk of low-privilege attackers reaching vulnerable handlers.
- Disable remote management from untrusted network segments until a patched firmware version is deployed.
Patch Information
The vendor recommends upgrading the affected component. Check the H3C Software Download Page and the H3C Product Details Theme for the latest firmware release addressing this issue. Apply the update to all H3C GR-3000AX devices running firmware V100R006 or earlier.
Workarounds
- Segment router management interfaces onto a dedicated administrative network isolated from user endpoints.
- Apply access control lists that permit HTTP POST requests to /goform/aspForm only from authorized management workstations.
- Monitor for and block requests containing abnormally large parameter values at an upstream network security device.
# Example: restrict router management access via firewall ACL
# Replace 10.0.0.5 with your authorized management host and
# 192.168.1.1 with the router's management IP.
iptables -A FORWARD -s 10.0.0.5 -d 192.168.1.1 -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
