Mitigation Strategies

Immediate mitigation steps include restricting access to the router's management interface to trusted networks or IP addresses to prevent unauthorized HTTP requests.

If possible, disable remote management features temporarily until a firmware update or patch is applied.

Monitor the router for crashes or instability that may indicate exploitation attempts.

Contact Shenzhen Tenda Technology Co., Ltd or check their official channels for firmware updates addressing this vulnerability and apply them as soon as they become available.

Useful 0 Not Useful 0

Executive Summary

The CVE-2026-36801 vulnerability is a buffer overflow issue in the Tenda G0 router firmware, specifically in the formIPMacBindAdd function of version V15.11.0.5.

This flaw happens when an attacker sends a crafted HTTP request to the formIPMacBindAdd CGI endpoint with an excessively long IPMacBindRule parameter, such as a string of 888 or more 'a' characters.

The vulnerability is triggered by a strcpy operation in the ipMacBindListStore function, which copies the malicious input into a fixed-size buffer, causing a buffer overflow.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability can be exploited to cause a Denial of Service (DoS) on the affected device.

The buffer overflow can lead to process crashes or device instability, potentially making the router unusable until it is restarted or fixed.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by monitoring HTTP requests sent to the Tenda G0 router's formIPMacBindAdd CGI endpoint. Specifically, look for HTTP requests containing the IPMacBindRule parameter with an unusually long string (e.g., 888 or more characters). Such requests may indicate an attempt to exploit the buffer overflow.

A possible detection method is to capture and analyze network traffic targeting the router's management interface, filtering for HTTP POST or GET requests to the formIPMacBindAdd endpoint with suspiciously long IPMacBindRule parameters.

Example command using tcpdump to capture relevant HTTP traffic:

• tcpdump -i <interface> -A 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)' | grep 'formIPMacBindAdd'

Alternatively, use tools like Wireshark to filter HTTP requests containing 'formIPMacBindAdd' and inspect the IPMacBindRule parameter length.

Useful 0 Not Useful 0