CVE-2025-15047: Tenda WH450 Buffer Overflow Vulnerability

CVE-2025-15047 Overview

CVE-2025-15047 is a stack-based buffer overflow in the Tenda WH450 router firmware version 1.0.0.18. The flaw resides in the HTTP request handler for the /goform/PPTPDClient endpoint, where the Username argument is processed without proper bounds checking. Attackers can trigger the overflow remotely without authentication by sending a crafted HTTP request. The vulnerability is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer). Public exploit details have been published, increasing the risk of opportunistic exploitation against exposed devices.

Critical Impact
Unauthenticated remote attackers can corrupt stack memory on Tenda WH450 routers, potentially achieving arbitrary code execution and full device compromise.

Affected Products

Tenda WH450 router (hardware)
Tenda WH450 firmware version 1.0.0.18
Devices exposing the /goform/PPTPDClient HTTP endpoint

Discovery Timeline

2025-12-23 - CVE-2025-15047 published to NVD
2026-02-24 - Last updated in NVD database

Technical Details for CVE-2025-15047

Vulnerability Analysis

The vulnerability exists in the HTTP request handler that processes requests to /goform/PPTPDClient. This endpoint manages Point-to-Point Tunneling Protocol (PPTP) client configuration on the device. When the handler parses the Username parameter from the incoming request, it copies the attacker-supplied value into a fixed-size stack buffer without enforcing length limits. Supplying an oversized Username value overwrites adjacent stack memory, including the saved return address.

Because the device runs the affected service on its network interface and requires no authentication for exploitation, an attacker on the same network segment, or any network reachable to the management interface, can trigger the condition with a single HTTP POST request. Successful exploitation can crash the device or, with a crafted payload, redirect execution flow to attacker-controlled code, granting arbitrary code execution at the privilege level of the web service process.

Root Cause

The root cause is missing input validation on the Username argument in the PPTPDClient form handler. The code uses an unsafe string copy operation against a stack-allocated buffer of fixed size, characteristic of [CWE-119] memory boundary failures common in consumer router firmware written in C.

Attack Vector

Attackers send an HTTP request to /goform/PPTPDClient with an oversized Username parameter. The request requires no credentials and no user interaction. Exploitation is possible across the network, including from the WAN side if the management interface is exposed. Public proof-of-concept reproduction steps are documented in the GitHub PoC Repository.

The vulnerability mechanism is documented publicly; refer to the PoC reproduction steps and the VulDB entry #337852 for technical specifics.

Detection Methods for CVE-2025-15047

Indicators of Compromise

HTTP POST requests to /goform/PPTPDClient containing unusually long Username parameter values
Unexpected reboots, watchdog resets, or HTTP service crashes on Tenda WH450 devices
Outbound connections from the router to unknown hosts following inbound requests to the management interface
Modified router configuration entries related to PPTP client settings without administrator action

Detection Strategies

Inspect web server logs on the router for requests targeting /goform/PPTPDClient with oversized parameters
Deploy network-based intrusion detection signatures matching long Username fields in HTTP request bodies destined for Tenda management endpoints
Monitor for HTTP responses that indicate crashes such as connection resets following requests to /goform/PPTPDClient

Monitoring Recommendations

Log all administrative HTTP traffic to network infrastructure devices and forward to a central analytics platform
Alert on repeated requests to /goform/PPTPDClient from a single source within short time windows
Track router uptime and service availability metrics to detect exploitation-induced crashes

How to Mitigate CVE-2025-15047

Immediate Actions Required

Restrict access to the router's HTTP management interface to trusted internal management VLANs only
Disable WAN-side remote management on affected Tenda WH450 devices
Disable the PPTP client feature if it is not in active use
Audit firewall rules to block inbound traffic to TCP ports hosting the web management interface from untrusted networks

Patch Information

At the time of publication, no vendor patch is referenced in the available advisories for Tenda WH450 firmware 1.0.0.18. Administrators should monitor the Tenda Official Website for firmware updates addressing this issue and apply them as soon as they are released. If no fix is forthcoming, evaluate replacement of the affected device with a supported model.

Workarounds

Place affected devices behind an upstream firewall that filters HTTP requests to /goform/PPTPDClient
Apply ACLs limiting which source IP addresses can reach the router management interface
Segment vulnerable routers into isolated network zones away from production assets
Replace end-of-life or unpatched Tenda WH450 hardware if a vendor fix is not available

bash

# Example: block inbound access to the router management interface using iptables on an upstream Linux gateway
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