Wavlink WL-WN579X3-C Stack-Based Buffer Overflow Vulnerability in Firewall CGI

A stack-based buffer overflow vulnerability has been identified in the Wavlink WL-WN579X3-C router, specifically in version 231124. The issue arises in the function sub_40139C within the file /cgi-bin/firewall.cgi. The vulnerability can be exploited remotely by manipulating the del_flag argument, leading to unauthorized memory access and potential code execution.

Impact

Exploitation of this vulnerability causes a stack-based buffer overflow, which can allow for arbitrary code execution on the device.

Reproduction

The vulnerability can be reproduced by sending a POST request to /cgi-bin/firewall.cgi with the firewall parameter set to singlePortForwardDelete. The del_flag parameter must be filled with a payload that exceeds the buffer size, causing a stack-based overflow.

Remediation

Users are advised to upgrade to Wavlink WL-WN579X3-C version 20260226, which addresses this vulnerability.