CVE-2026-121598

Summary

A stack-based buffer overflow in the strcpy call within the Basic Wireless Configuration Handler of TOTOLINK A950RG firmware v4.1.2cu.5268_B20221104 allows remote attackers to overwrite the stack via the 'wepkey' parameter in /cgi-bin/cstecgi.cgi, leading to potential code execution.

Exploitability

Exploitation is straightforward for authenticated low-privilege users (PR:L) over the network with no user interaction required (AV:N/AC:L/UI:N), and a public exploit exists.

Blast radius

Successful exploitation could lead to full compromise of the device, including remote code execution, data exfiltration, and use as a pivot point within the local network.

Detection

Look for HTTP POST requests to /cgi-bin/cstecgi.cgi with an unusually long 'wepkey' parameter value (>64 bytes) in web server or application logs; no reliable host-based artefact is described.

Prioritized remediation

Upgrade to firmware version 4.1.2cu.5268_B20230101 or later (if such a patch exists); if no patched version is publicly confirmed, disable the affected 'Basic Wireless Configuration' CGI endpoint and restrict access to it via firewall rules until vendor guidance is available.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.