Description
Incorrect access control in the setSmartQosCfg function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to degrade traffic handling via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
Published: 2026-08-31
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: QoS Degradation (Denial of Service)
Action: Patch
AI Analysis

Impact

The vulnerability originates from incorrect access control (CWE-284) in the setSmartQosCfg function of TOTOLINK T6. An unauthenticated attacker can send a crafted POST request to /cgi-bin/cstecgi.cgi to alter Quality of Service settings, causing traffic handling degradation on the device.

Affected Systems

TOTOLINK T6 routers running firmware version 4.1.5cu.748_B20211015. No vendor or product names are provided beyond the internal firmware identifier.

Risk and Exploitability

The flaw can be triggered without authentication, suggesting remote exploitation is possible via the router’s public or locally accessible CGI endpoint. The EPSS score indicates a low exploitation probability (<1%) and the vulnerability is not listed in the CISA KEV catalog, implying limited exploitation activity. With a CVSS score of 4.3, the vulnerability represents moderate severity and, with no publicly disclosed exploit code, the primary risk is a potential denial of service through QoS misconfiguration.

Generated by OpenCVE AI on September 2, 2026 at 04:46 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Identify the installed firmware version and download the latest TOTOLINK firmware from the vendor’s official site
  • Apply the firmware update to the router to resolve the access control flaw
  • If an update is unavailable, block or restrict access to /cgi-bin/cstecgi.cgi through the router’s firewall or disable QoS configuration features to prevent misuse

Generated by OpenCVE AI on September 2, 2026 at 04:46 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 02 Sep 2026 05:15:00 +0000

Type Values Removed Values Added
Title Unauthenticated Access Control Bypass Enables Traffic QoS Degradation on TOTOLINK T6 Router

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 31 Aug 2026 17:15:00 +0000

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

Mon, 31 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Title Unauthenticated Access Control Bypass Enables Traffic QoS Degradation on TOTOLINK T6 Router
Weaknesses CWE-284

Mon, 31 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description Incorrect access control in the setSmartQosCfg function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to degrade traffic handling via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
References

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-01T16:52:05.812Z

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

Link: CVE-2026-51706

cve-icon Vulnrichment

Updated: 2026-09-01T16:52:00.534Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T16:18:35.790

Modified: 2026-09-01T17:17:30.933

Link: CVE-2026-51706

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-02T05:00:13Z

Weaknesses