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CRITICAL

DBLTek GoIP Telnet Admin Interface Undocumented Backdoor

Published Oct 15, 2025

Description

DBLTek GoIP devices (models GoIP 1, 4, 8, 16, and 32) contain an undocumented vendor backdoor in the Telnet administrative interface that allows remote authentication as an undocumented user via a proprietary challenge–response scheme which is fundamentally flawed. Because the challenge response can be computed from the challenge itself, a remote attacker can authenticate without knowledge of a secret and obtain a root shell on the device. This can lead to persistent remote code execution, full device compromise, and arbitrary control of the device and any managed services. The firmware used within these devices was updated in December 2016 to make this vulnerability more complex to exploit. However, it is unknown if DBLTek has taken steps to fully mitigate.

Affected products

Remediation

No remediation recorded yet.

Metrics

Weaknesses (1)

References (4)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner VulnCheck
Published Oct 15, 2025
Updated Oct 15, 2025
Reserved Oct 14, 2025
CISA Vulnrichment
Updated Oct 15, 2025
NVD
Status Deferred
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a