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

Published Jul 20, 2025
·
Updated

A vulnerability has been found in TOTOLINK T6 4.1.5cu.748B20211015 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 telnetenabled 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.

Affected Software

3 affected components
TOTOLINK T6
All of the following
TOTOLINK T6 Firmware=v4.1.5cu.748_b20211015
TOTOLINK T6=3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Configuration

    Set telnet_enabled to 0 (disable Telnet) to prevent the missing authentication condition triggered by manipulation of the telnet_enabled argument with input 1.

    TOTOLINK T6 Telnet Service (cgi-bin/cstecgi.cgi setTelnetCfg) telnet_enabled = 0
  2. Compensating control

    Restrict remote access to the Telnet Service (cstecgi.cgi /cgi-bin/cstecgi.cgi) at the network/ACL level until the issue is remediated, since the attack can be launched remotely.

Event History

Jul 20, 2025
CVE Published
via MITRE·02:02 AM
Data Sourced
via MITRE·02:02 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 AM
DescriptionSeverityWeaknessAffected Software
Jun 22, 58473
Event
via NVD·10:02 AM
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Frequently Asked Questions

1

What is the severity of CVE-2025-7862?

CVE-2025-7862 is classified as a critical vulnerability.

2

What component is affected by CVE-2025-7862?

CVE-2025-7862 affects the Telnet Service in the TOTOLINK T6 device.

3

How do I fix CVE-2025-7862?

To fix CVE-2025-7862, disable the Telnet service in the device settings.

4

What function is exploited in CVE-2025-7862?

CVE-2025-7862 exploits the function setTelnetCfg in the cgi-bin/cstecgi.cgi file.

5

Which devices are affected by CVE-2025-7862?

CVE-2025-7862 affects the TOTOLINK T6 version 4.1.5cu.748_B20211015.

Contact

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