TOTOLINK A810R Buffer Overflow Vulnerability in downloadFile.cgi

A buffer overflow vulnerability has been identified in the TOTOLINK A810R router, specifically in the firmware version V4.1.2cu.5182_B20201026. The issue arises in the downloadFile.cgi file, where user-supplied input is not properly validated before being copied into a buffer, allowing for potential memory corruption.

Impact

Exploitation of this vulnerability leads to a buffer overflow condition, which can commonly result in arbitrary code execution or causing the device to crash.

Reproduction

To reproduce this vulnerability, send a request to the downloadFile.cgi endpoint with a payload that includes the v14 parameter. The v5 parameter must contain data that exceeds 132 bytes, which will trigger the buffer overflow by overwriting adjacent memory.