CVE-2025-7862 TOTOLINK T6 Telnet Service cstecgi.cgi setTelnetCfg missing authentication

Medium 6.9 Published 20 Jul 2025 Updated 22 Jul 2025

Remote attackers can enable Telnet without authentication on TOTOLINK T6 routers, potentially leading to full device compromise.

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

What is CVE-2025-7862?

CVE-2025-7862 is a medium-severity missing authorization vulnerability in TOTOLINK T6, published on 20 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability has been found in TOTOLINK T6 4.1.5cu.748_B20211015 and classified as critical. Affected by this vulnerability is the function setTelnetCfg of the file /cgi-bin/cstecgi.cgi of the component Telnet Service. The manipulation of the argument telnet_enabled with the input 1 leads to missing authentication. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Weakness: CWE-306, CWE-287

Which versions are affected by CVE-2025-7862?

It affects 1 product.

Products include Totolink T6 Firmware.

How do I fix CVE-2025-7862?

No fix has been published for CVE-2025-7862 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2025-7862 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-7862 exists.

Sources

Also known as GHSA-vm25-8x3c-9vc3.