Tenda AC18 Stack-Based Buffer Overflow Vulnerability in DDNS Configuration

A stack-based buffer overflow vulnerability has been identified in the Tenda AC18 router running firmware version 15.03.05.19(6318). The issue arises in the '/goform/SetDDNSCfg' endpoint, where the 'ddnsEn' parameter is processed without proper length validation. This vulnerability can be exploited remotely, leading to potential arbitrary code execution.

Impact

Exploitation of this vulnerability causes a stack-based buffer overflow, which can commonly lead to arbitrary code execution on the device.

Reproduction

To reproduce this vulnerability, send a POST request to the '/goform/SetDDNSCfg' endpoint with the 'ddnsEn' parameter. The 'action' parameter must be set to 1. The 'ddnsEn' parameter can be crafted with a payload that exceeds the buffer size, triggering the overflow.