CVE-2025-7862: totolink t6_firmware Improper Authentication

Vulnerability summary

CVE-2025-7862 is a critical (CVSS 9.8) Improper Authentication vulnerability in totolink t6_firmware. EPSS estimates a 1.21% chance of exploitation in the next 30 days, higher than 68.2% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 20-07-2025
   PublishedVulnerability first disclosed.
2. 22-07-2025
   Last modifiedVulnerability information updated.

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.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
• CWE-306Missing Authentication for Critical FunctionThe product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.