Description
Incorrect access control in the LoadDefSettings function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to reset the device configuration and reboot the device via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
Published: 2026-08-31
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: Unauthenticated remote attacker can reset device configuration and force a reboot
Action: Immediate Fix
AI Analysis

Impact

The flaw resides in the LoadDefSettings routine of TOTOLINK T6 firmware 4.1.5cu.748_B20211015, where access control is not enforced. This omission lets an unauthenticated attacker craft a POST request to /cgi-bin/cstecgi.cgi and trigger a device configuration reset and reboot. The defect is an instance of improper access control, allowing loss of configuration state and potential service disruption.

Affected Systems

All devices running the affected firmware version of the TOTOLINK T6 router – firmware 4.1.5cu.748_B20211015 – are impacted. No other TOTOLINK models or firmware versions are known to be affected.

Risk and Exploitability

Unauthenticated or low‑privilege attackers can execute the exploit without needing credentials or additional access. Based on the description, it is inferred that the vulnerability is purely remote and does not require privileged privileges, leading to a high attack surface. The CVSS score of 9.8, combined with an EPSS score of less than 1 %, and the fact that it is not listed in CISA KEV, underline the severe operational impact of being able to reset configuration and reboot the device.

Generated by OpenCVE AI on September 3, 2026 at 14:56 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the latest firmware update released by TOTOLINK that resolves the LoadDefSettings access‑control issue
  • Configure network perimeter devices or the router itself to block or limit external access to /cgi-bin/cstecgi.cgi for unauthenticated clients
  • Enable traffic monitoring or intrusion detection to alert on repeated POST attempts to /cgi-bin/cstecgi.cgi

Generated by OpenCVE AI on September 3, 2026 at 14:56 UTC.

Tracking

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Advisories

No advisories yet.

History

Thu, 03 Sep 2026 15:15:00 +0000

Type Values Removed Values Added
Title Unauthorized Device Reset and Reboot via Improper Access Control

Wed, 02 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Wed, 02 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Mon, 31 Aug 2026 23:00:00 +0000

Type Values Removed Values Added
Title Unauthorized Device Reset and Reboot via Improper Access Control
Weaknesses CWE-284

Mon, 31 Aug 2026 22:30:00 +0000

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

Mon, 31 Aug 2026 20:00:00 +0000

Type Values Removed Values Added
Description Incorrect access control in the LoadDefSettings function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to reset the device configuration and reboot the device via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
References

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-02T16:02:53.987Z

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

Link: CVE-2026-51738

cve-icon Vulnrichment

Updated: 2026-09-02T13:57:01.334Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T20:17:05.103

Modified: 2026-09-02T16:17:17.313

Link: CVE-2026-51738

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T15:00:06Z

Weaknesses