D-Link Products Stack-Based Buffer Overflow Vulnerability in Account Management CGI

A stack-based buffer overflow vulnerability has been identified in multiple D-Link NAS devices, including the DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05, and DNS-1550-04, all running firmware versions prior to 20260205. The vulnerability resides in the 'cgi_adduser_to_session' function of the '/cgi-bin/account_mgr.cgi' file. It allows remote attackers to manipulate the 'read_list', 'write_list', and 'decline_list' parameters, leading to a stack-based buffer overflow. This overflow can be exploited to execute arbitrary code, causing the device to crash and disrupt services.

Impact

Exploitation of this vulnerability leads to a stack-based buffer overflow, allowing for arbitrary code execution. However, in the context of the proof-of-concept demonstration, the vulnerability was used to crash the device, causing a denial of service.

Reproduction

The vulnerability can be reproduced by sending a POST request to '/cgi-bin/account_mgr.cgi' with an excessively long 'read_list' parameter. This overloads the stack, overwriting the return address and causing a buffer overflow. The device will crash and fail to provide services correctly.