Description
Incorrect access control in the delStaticDhcpRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to remove static DHCP reservations 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 removal of static DHCP reservations leading to potential network disruption
Action: Immediate Patch
AI Analysis

Impact

The vulnerability resides in the delStaticDhcpRules function of TOTOLINK T6 firmware 4.1.5cu.748_B20211015. This is a CWE-284: Improper Access Control flaw. An attacker can send a crafted POST request to /cgi-bin/cstecgi.cgi and delete static DHCP reservations without authentication. This lack of access control allows any device that can reach the router’s management interface to alter critical network configuration. Removing reservations can cause IP conflicts, deny service to designated clients, or enable attackers to capture those addresses.

Affected Systems

Vendor TOTOLINK, product T6 running firmware 4.1.5cu.748_B20211015. No other affected versions are listed in the CVE data.

Risk and Exploitability

The EPSS score is below 1% and the vulnerability is not listed in the CISA KEV catalog. The CVSS score of 9.8 indicates critical severity. The attack can be conducted remotely via HTTP by an unauthenticated attacker with network access to the router. The exploitation path is straightforward: send a crafted POST request to the vulnerable CGI endpoint, causing the deletion of static DHCP reservations. The impact is immediate and could disrupt network connectivity or facilitate further attacks.

Generated by OpenCVE AI on September 1, 2026 at 17:29 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the router to a firmware release that resolves the access control flaw
  • Limit external exposure of the router’s management interface by blocking HTTP/HTTPS ports on the public network or by moving the device to a separate VLAN
  • Configure firewall rules to reject POST requests to /cgi-bin/cstecgi.cgi from IP addresses outside the local subnet

Generated by OpenCVE AI on September 1, 2026 at 17:29 UTC.

Tracking

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Advisories

No advisories yet.

History

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

Type Values Removed Values Added
Title Unauthenticated Deletion of Static DHCP Reservations in TOTOLINK T6

Tue, 01 Sep 2026 14:30:00 +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 18:00:00 +0000

Type Values Removed Values Added
Title Unauthenticated Deletion of Static DHCP Reservations in TOTOLINK T6
Weaknesses CWE-284

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

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

Mon, 31 Aug 2026 16:15:00 +0000

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

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-01T13:48:10.372Z

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

Link: CVE-2026-51718

cve-icon Vulnrichment

Updated: 2026-09-01T13:48:07.419Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T16:18:36.970

Modified: 2026-09-01T14:17:32.570

Link: CVE-2026-51718

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-01T17:30:17Z

Weaknesses