TOTOLINK A702R Buffer Overflow Vulnerability in QoS Management Function

A buffer overflow vulnerability has been identified in the TOTOLINK A702R router, specifically in firmware version 4.0.0-B20211108.1423. The issue arises in the 'sub_419BE0' function within the '/boafrm/formIpQoS' endpoint. This vulnerability can be exploited remotely by manipulating the 'mac' argument, potentially leading to a program crash.

Impact

Exploitation of this vulnerability causes a buffer overflow, which can commonly lead to arbitrary code execution or causing the device to crash.

Reproduction

The vulnerability can be reproduced by sending a POST request to the '/boafrm/formIpQoS' endpoint. The request must include a 'mac' parameter that is excessively long, exceeding the buffer size that the application can safely handle. This can be done using a web browser or a tool like curl, by specifying the 'mac' parameter in the request body.