Description
Incorrect access control in the setDdnsCfg function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to alter dynamic DNS state via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
Published: 2026-08-31
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: Unauthorized modification of dynamic DNS configuration
Action: Apply Patch
AI Analysis

Impact

The vulnerability resides in the setDdnsCfg function of TOTOLINK T6 firmware 4.1.5cu.748_B20211015. An unauthenticated attacker can send a crafted POST request to /cgi-bin/cstecgi.cgi that bypasses the expected authentication check, allowing the attacker to toggle the dynamic DNS feature on or off.

Affected Systems

Devices from the TOTOLINK T6 series that are running firmware version 4.1.5cu.748_B20211015 are impacted. The vendor’s coordination pages reference this specific firmware release. No other firmware versions or devices have been identified as affected.

Risk and Exploitability

The vulnerability requires only unauthenticated network access to the device and does not rely on additional privileges or sophisticated exploitation steps, and is rated high with a CVSS score of 7.5. No public exploitation has been reported, and the vulnerability is not listed in the CISA KEV catalog. The endpoint is accessible over the network interface. The EPSS score of < 1% indicates a low likelihood of exploitation.

Generated by OpenCVE AI on September 2, 2026 at 05:12 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the firmware update supplied by TOTOLINK that addresses the access control flaw
  • If a firmware update is not yet available, block external access to the /cgi-bin/cstecgi.cgi endpoint using firewall or router rules
  • Disable the dynamic DNS feature in the device’s configuration until a secure update can be applied

Generated by OpenCVE AI on September 2, 2026 at 05:12 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 02 Sep 2026 05:30:00 +0000

Type Values Removed Values Added
Title Unauthenticated Dynamic DNS Configuration Alteration in TOTOLINK T6 Firmware

Tue, 01 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 31 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Title Unauthenticated Dynamic DNS Configuration Alteration in TOTOLINK T6 Firmware
Weaknesses CWE-284

Mon, 31 Aug 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Totolink
Totolink t6
Vendors & Products Totolink
Totolink t6

Mon, 31 Aug 2026 15:15:00 +0000

Type Values Removed Values Added
Description Incorrect access control in the setDdnsCfg function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to alter dynamic DNS state via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
References

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-01T14:15:00.880Z

Reserved: 2026-06-08T00:00:00.000Z

Link: CVE-2026-51695

cve-icon Vulnrichment

Updated: 2026-09-01T14:14:56.562Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T15:17:21.243

Modified: 2026-09-01T15:17:15.953

Link: CVE-2026-51695

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-02T05:15:05Z

Weaknesses