Tenda F451 Router Stack-Based Buffer Overflow Vulnerability

A stack-based buffer overflow vulnerability has been identified in Tenda F451 router version 1.0.0.7. The vulnerability resides within the formWrlsafeset function of the /goform/AdvSetWrlsafeset file. A remote attacker can exploit this flaw by crafting a malicious request with an overly long mit_ssid argument, leading to potential arbitrary code execution on the device. Public exploits for this vulnerability are available, making it imperative for users of affected Tenda devices to take immediate action. This vulnerability poses a significant risk, as successful exploitation could grant an attacker full control over the vulnerable device.

Attack Chain

1. The attacker identifies a Tenda F451 router running firmware version 1.0.0.7 exposed to the internet.
2. The attacker crafts a malicious HTTP POST request targeting the /goform/AdvSetWrlsafeset endpoint.
3. The crafted request includes the mit_ssid argument with a string exceeding the buffer's expected size.
4. The router's web server processes the request and passes the mit_ssid argument to the formWrlsafeset function.
5. Due to the insufficient bounds checking, the overly long mit_ssid value overflows the stack-based buffer.
6. The buffer overflow overwrites critical data on the stack, including the return address.
7. The attacker carefully crafts the overflowed data to redirect execution to a location containing malicious code.
8. The malicious code executes with the privileges of the web server process, potentially granting the attacker full control of the device.

Impact

Successful exploitation of this vulnerability allows a remote attacker to execute arbitrary code on the affected Tenda F451 router. This can lead to complete compromise of the device, allowing the attacker to modify router settings, intercept network traffic, or use the device as a botnet node. Given the widespread use of Tenda routers, this vulnerability has the potential to impact a large number of users and networks.

Recommendation

• Apply any available firmware updates released by Tenda to patch CVE-2026-5988.
• Deploy the Sigma rule Detect Suspicious AdvSetWrlsafeset Request to detect exploitation attempts targeting the vulnerable endpoint.
• Monitor web server logs for unusually long mit_ssid parameters in requests to /goform/AdvSetWrlsafeset.