D-Link DWR-M920 Buffer Overflow Vulnerability in Parent Control Function

A buffer overflow vulnerability has been identified in the D-Link DWR-M920 router, specifically in version 1.1.50. This issue also affects the D-Link DIR-822K router running the same version. The vulnerability arises in the 'formParentControl' route, within the 'sub_423848' function, where the 'submit-url' parameter is processed without proper length validation. This flaw allows for remote exploitation, leading to a crash of the device.

Impact

Exploitation of this vulnerability causes a buffer overflow, which can commonly lead to arbitrary code execution or a denial-of-service condition, causing the device to crash or become unresponsive.

Reproduction

To reproduce this vulnerability, send a POST request to the '/boafrm/formParentControl' endpoint with a crafted 'submit-url' parameter that exceeds the buffer limit. After the request is processed, visiting the router's main page will trigger the crash, demonstrating the successful exploitation of the buffer overflow.