CVE-2025-4496 TOTOLINK T10/A3100R/A950RG/A800R/N600R/A3000RU/A810R cstecgi.cgi CloudACMunualUpdate buffer overflow

High 8.7 Published 10 May 2025 Updated 12 May 2025

Remote attackers can trigger a buffer overflow in the CloudACMunualUpdate function of TOTOLINK routers, potentially leading to arbitrary code execution.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-4496?

CVE-2025-4496 is a high-severity memory corruption vulnerability in TOTOLINK A3000RU, published on 10 May 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability was found in TOTOLINK T10, A3100R, A950RG, A800R, N600R, A3000RU and A810R 4.1.8cu.5241_B20210927. It has been declared as critical. This vulnerability affects the function CloudACMunualUpdate of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument FileName leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.

Weakness: CWE-120, CWE-119

Which versions are affected by CVE-2025-4496?

It affects 7 products.

Products include Totolink A3000ru Firmware, Totolink A3100r Firmware, Totolink A800r Firmware, Totolink A810r Firmware, Totolink A950rg Firmware, Totolink N600r Firmware and 1 more.

How do I fix CVE-2025-4496?

No fix has been published for CVE-2025-4496 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-4496 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-4496 exists.

Sources

Also known as GHSA-96qf-wf2v-wxvc.