Tenda AC9 Stack-Based Buffer Overflow Vulnerability in WizardHandle POST Request Handler

A stack-based buffer overflow vulnerability has been identified in the Tenda AC9 router, specifically in the 15.03.02.13 firmware version. The issue arises in the 'decodePwd' function within the '/goform/WizardHandle' file, part of the POST Request Handler component. The vulnerability can be exploited remotely by manipulating the 'WANS' parameter of a POST request, leading to potential overwriting of the stack and execution of arbitrary code.

Impact

Exploitation of this vulnerability causes a stack-based buffer overflow, which can lead to arbitrary code execution by overwriting the return address of a function on the stack.

Reproduction

To reproduce this vulnerability, send a POST request to the '/goform/WizardHandle' endpoint with a crafted 'WANS' parameter that exceeds the buffer capacity of the 'decodePwd' function. This will trigger the stack-based buffer overflow by overwriting the return address on the stack.