CVE-2025-7795: Tenda FH451 Buffer Overflow Vulnerability

CVE-2025-7795 Overview

CVE-2025-7795 is a stack-based buffer overflow vulnerability in the Tenda FH451 router running firmware version 1.0.0.9. The flaw resides in the fromP2pListFilter function handling requests to the /goform/P2pListFilter endpoint. Attackers can manipulate the page argument to trigger memory corruption on the stack. The vulnerability is remotely exploitable over the network and a public exploit has been disclosed, increasing the likelihood of opportunistic attacks against exposed devices. The issue is tracked as VulDB #316856 and is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.

Critical Impact
Remote attackers with low privileges can corrupt stack memory on Tenda FH451 routers, potentially achieving arbitrary code execution and full device compromise.

Affected Products

Tenda FH451 router (hardware)
Tenda FH451 firmware version 1.0.0.9
Endpoint /goform/P2pListFilter invoking the fromP2pListFilter handler

Discovery Timeline

2025-07-18 - CVE-2025-7795 published to NVD
2025-07-23 - Last updated in NVD database

Technical Details for CVE-2025-7795

Vulnerability Analysis

The Tenda FH451 firmware exposes a web management interface that processes HTTP requests through several /goform/ handlers. The fromP2pListFilter function parses the page query parameter without validating its length before copying it into a fixed-size stack buffer. Supplying an oversized value overflows adjacent stack memory, including saved registers and the return address.

The vulnerability falls under [CWE-119] and is exploitable remotely. An EPSS score of 18.16% (95th percentile) signals elevated likelihood of exploitation activity relative to the broader CVE population. Public proof-of-concept material is hosted on the panda666-888 vulnerability research repository.

Root Cause

The fromP2pListFilter handler reads the user-supplied page parameter and copies it into a stack-allocated buffer using an unchecked copy operation. No length validation, bounds checking, or input sanitization is performed. This pattern is recurrent across Tenda firmware web handlers and stems from direct use of unsafe C string functions on attacker-controlled CGI input.

Attack Vector

An authenticated attacker sends a crafted HTTP request to /goform/P2pListFilter with an oversized page parameter. Because the router web service runs with elevated privileges on the embedded Linux system, successful exploitation can yield arbitrary code execution as the web daemon. Devices exposed to the internet or reachable from adjacent network segments face the highest risk.

No verified exploit code is reproduced here. Refer to the GitHub vulnerability documentation for the public proof-of-concept details.

Detection Methods for CVE-2025-7795

Indicators of Compromise

HTTP requests to /goform/P2pListFilter containing unusually long page parameter values
Web service (httpd) crashes, restarts, or watchdog reboots on Tenda FH451 devices
Unexpected outbound connections from the router to attacker-controlled infrastructure
New or modified processes running on the router post-exploitation

Detection Strategies

Inspect web access logs for POST or GET requests targeting /goform/P2pListFilter with parameter lengths exceeding typical pagination values
Deploy network IDS signatures matching oversized page= parameters in HTTP requests to FH451 management endpoints
Monitor SNMP and syslog feeds from network devices for unexpected reboots or service restarts indicative of memory corruption

Monitoring Recommendations

Forward router syslog and HTTP access logs to a centralized SIEM for correlation and anomaly detection
Baseline normal management traffic patterns and alert on deviations targeting /goform/ endpoints
Restrict management interface access to a dedicated administrative VLAN and monitor any traffic crossing that boundary

How to Mitigate CVE-2025-7795

Immediate Actions Required

Disable remote (WAN-side) administration on all Tenda FH451 devices until a vendor patch is applied
Restrict LAN-side access to the web management interface to a small set of trusted administrative hosts
Rotate administrative credentials, given that exploitation requires low-privilege authentication
Audit device logs for prior requests to /goform/P2pListFilter containing oversized parameters

Patch Information

At the time of NVD publication, no vendor advisory or patched firmware release has been published by Tenda. Monitor the Tenda official website for firmware updates addressing the fromP2pListFilter handler. Organizations operating affected devices in production should evaluate replacement with supported hardware if a patch is not made available in a reasonable timeframe.

Workarounds

Place affected routers behind an upstream firewall that blocks inbound HTTP/HTTPS to the management interface
Apply ACLs that permit access to /goform/P2pListFilter only from designated administrative source IP addresses
Segment FH451 devices onto isolated network zones to limit lateral exposure if a device is compromised
Decommission internet-exposed FH451 units lacking a patch path

bash

# Example: block external access to the Tenda web management port using an upstream Linux firewall
iptables -A FORWARD -p tcp -d <ROUTER_IP> --dport 80 -m iprange ! --src-range 10.0.0.10-10.0.0.20 -j DROP
iptables -A FORWARD -p tcp -d <ROUTER_IP> --dport 443 -m iprange ! --src-range 10.0.0.10-10.0.0.20 -j DROP