Description
Incorrect access control in the delMacFilterRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to remove MAC filter rules 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: Unauthorized removal of MAC filtering rules
Action: Apply patch
AI Analysis

Impact

The vulnerability is an incorrect access control flaw in the delMacFilterRules function of TOTOLINK T6 (firmware 4.1.5cu.748_B20211015). Unauthenticated attackers can send a crafted POST request to /cgi-bin/cstecgi.cgi to delete MAC filter rules. Removing these rules lifts the enforced MAC address whitelist, which weakens network access control. The effect of allowing devices to connect without the whitelist is inferred from the function’s purpose, not explicitly stated in the advisory.

Affected Systems

The flaw affects TOTOLINK T6 routers running firmware version 4.1.5cu.748_B20211015 from the public build release. Devices using other firmware versions are not impacted.

Risk and Exploitability

The flaw can be exploited remotely by any host that can reach the router’s HTTP interface to submit a POST request, as no authentication is required. Exploitation requires only network connectivity to the management interface. The EPSS score is <1%, and the vulnerability is not listed in CISA KEV. The CVSS score of 9.8 marks it as critical. The attack vector is likely local network or any machine with access to the router’s web interface.

Generated by OpenCVE AI on September 2, 2026 at 05:33 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the router firmware to a version that contains the access control fix
  • If no newer firmware is available, block remote access to /cgi-bin/cstecgi.cgi through a firewall or router ACL to prevent unauthenticated POST requests
  • After mitigating the vulnerability, re‑apply MAC filter rules and verify that deletion of the list is no longer possible without authentication

Generated by OpenCVE AI on September 2, 2026 at 05:33 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 02 Sep 2026 06:00:00 +0000

Type Values Removed Values Added
Title Unauthenticated Deletion of MAC Filter Rules in TOTOLINK T6

Tue, 01 Sep 2026 15:30:00 +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'}

ssvc

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

Mon, 31 Aug 2026 17:45:00 +0000

Type Values Removed Values Added
Title Unauthenticated Deletion of MAC Filter Rules in TOTOLINK T6
First Time appeared Totolink
Totolink t6
Weaknesses CWE-284
Vendors & Products Totolink
Totolink t6

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

Type Values Removed Values Added
Description Incorrect access control in the delMacFilterRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to remove MAC filter rules via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
References

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-01T14:28:01.673Z

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

Link: CVE-2026-51715

cve-icon Vulnrichment

Updated: 2026-09-01T14:23:42.793Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T16:18:36.647

Modified: 2026-09-01T15:17:17.463

Link: CVE-2026-51715

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-02T05:45:04Z

Weaknesses