D-Link DI-8100 Buffer Overflow Vulnerability in qj_asp Function Allowing Denial-of-Service

A buffer overflow vulnerability has been identified in the D-Link DI-8100 router, specifically in firmware version 16.07.26A1. The issue arises in the qj_asp function of the jhttpd web server, where the en, val, and id parameters can be manipulated. Authenticated attackers can exploit this vulnerability by sending crafted GET requests with excessively long values, leading to a stack overflow. This exploitation causes the router to crash, resulting in a denial-of-service condition.

Impact

Exploitation of this vulnerability causes a stack overflow, leading to a crash of the router and a denial-of-service condition.

Reproduction

The vulnerability can be reproduced by logging into the router and accessing the qj.asp page. Once there, send a GET request with the val parameter set to a value long enough to overflow the stack. This can be done using a Python script that logs into the router and then sends the crafted request.