Tenda F453 Stack-Based Buffer Overflow Vulnerability

A critical stack-based buffer overflow vulnerability, identified as CVE-2026-4551, has been discovered in Tenda F453 version 1.0.0.3. The vulnerability resides within the fromSafeClientFilter function of the /goform/SafeClientFilter component, specifically in the Parameters Handler. Successful exploitation can occur remotely and allows attackers to execute arbitrary code on the affected device. Publicly available exploits exist, increasing the risk of widespread exploitation. Routers are often targeted due to their perimeter position and the potential to compromise entire networks. Defenders should prioritize patching and implement detection measures to mitigate the risk.

Attack Chain

1. The attacker identifies a Tenda F453 router running firmware version 1.0.0.3.
2. The attacker crafts a malicious HTTP request targeting the /goform/SafeClientFilter endpoint.
3. The attacker injects a payload into the menufacturer/Go argument within the HTTP request.
4. The fromSafeClientFilter function processes the attacker-controlled input without proper bounds checking.
5. The oversized input overflows the stack-based buffer.
6. The overflow overwrites critical data on the stack, including the return address.
7. The attacker gains arbitrary code execution on the router, potentially leading to full system compromise.

Impact

Successful exploitation of CVE-2026-4551 allows a remote attacker to execute arbitrary code on the Tenda F453 router. This can lead to a complete compromise of the device, potentially enabling attackers to intercept network traffic, modify router settings, or use the device as a botnet node. While the exact number of affected devices is unknown, the public availability of exploits significantly increases the risk of widespread exploitation and potential damage to home and small business networks.

Recommendation

• Apply available patches or firmware updates provided by Tenda for the F453 router to address CVE-2026-4551 (refer to Tenda's website for updates).
• Monitor web server logs for suspicious POST requests to /goform/SafeClientFilter with unusually long menufacturer or Go parameters (see Sigma rule below).
• Implement rate limiting on HTTP POST requests to the /goform/SafeClientFilter endpoint to mitigate potential exploitation attempts.