Tenda AC6 Stack Overflow Vulnerability in saveParentControlInfo Function

A stack overflow vulnerability has been identified in the Tenda AC6 router, specifically in the firmware version V15.03.06.23_multi. The issue arises in the saveParentControlInfo function, where user-supplied data in the deviceName parameter is not properly validated, allowing for a buffer overflow on the stack.

Impact

Exploitation of this vulnerability leads to a stack-based buffer overflow, which can commonly result in arbitrary code execution or causing the device to crash.

Reproduction

The vulnerability can be reproduced by sending a POST request to the /goform/saveParentControlInfo endpoint. The request must include a crafted deviceName parameter that exceeds the buffer limit, causing a stack overflow. This can be done by using a deviceName value that is significantly longer than the maximum allowed size.