RE11S Stack Overflow Vulnerability in PPPoE Setup Function

A stack overflow vulnerability has been identified in RE11S version 1.11. The issue arises in the formPPPoESetup function, where the pppUserName parameter can be manipulated to cause a buffer overflow. This vulnerability was discovered during an internship at Qi An Xin Tiangong Lab, while analyzing the router's web interface.

Impact

Exploitation of this vulnerability leads to a stack overflow, allowing for potential arbitrary code execution or causing a denial-of-service condition by crashing the device.

Reproduction

The vulnerability can be reproduced by sending a POST request to the '/goform/formPPPoESetup' endpoint with a crafted pppUserName parameter. The payload should be designed to exceed the buffer size, causing a stack overflow. This can be automated with a Python script that uses the requests library to send the malicious payload.