Description
Incorrect access control in the setIpPortFilterRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to alter firewall policies 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: Unauthorized modification of router firewall policies
Action: Assess Impact
AI Analysis

Impact

The vulnerability resides in the setIpPortFilterRules function of TOTOLINK T6 firmware 4.1.5cu.748_B20211015, where access controls are not enforced, allowing an unauthenticated attacker to send a crafted POST request to /cgi-bin/cstecgi.cgi and alter firewall rules. This permits an attacker to bypass or modify network protection policies, potentially enabling unauthorized network access or data exfiltration. The weakness is an improper authorization flaw (CWE-284).

Affected Systems

Affected devices are TOTOLINK T6 routers operating firmware version 4.1.5cu.748_B20211015. No other vendor or product versions are listed in the CVE data.

Risk and Exploitability

The CVE has a CVSS score of 4.3, an EPSS score of < 1%, and is not listed in the CISA KEV catalog. Nevertheless, the attack vector is network-based, requiring no authentication and a crafted POST payload, making exploitation relatively straightforward for an attacker who can reach the device. Because the attacker can change firewall rules, the risk of compromise and network disruption remains high even though the quantified severity metric is moderate.

Generated by OpenCVE AI on September 2, 2026 at 02:28 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Verify the firmware version of all TOTOLINK T6 routers in the network and identify those running 4.1.5cu.748_B20211015.
  • Update the affected routers to the latest firmware that addresses the access control flaw, as released by TOTOLINK; if no patch is available, check the vendor's website or contact support for a fix.
  • If an update cannot be applied, restrict access to the /cgi-bin/cstecgi.cgi endpoint by configuring network firewalls or router ACLs to permit the interface only from trusted management IPs or by disabling the feature through router configuration if possible.
  • Enable logging on the router to detect and alert on unauthorized POST requests to /cgi-bin/cstecgi.cgi, and regularly review logs for suspicious activity.

Generated by OpenCVE AI on September 2, 2026 at 02:28 UTC.

Tracking

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Advisories

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History

Wed, 02 Sep 2026 02:45:00 +0000

Type Values Removed Values Added
Title Unauthenticated Router Firewall Rule Modification via Incorrect Access Control

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:L/A:N'}

ssvc

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

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

Type Values Removed Values Added
Title Unauthenticated Router Firewall Rule Modification via Incorrect Access Control
First Time appeared Totolink
Totolink t6
Weaknesses CWE-284
Vendors & Products Totolink
Totolink t6

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

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

Subscriptions

Totolink T6
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-09-01T16:48:07.862Z

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

Link: CVE-2026-51702

cve-icon Vulnrichment

Updated: 2026-09-01T16:48:03.396Z

cve-icon NVD

Status : Deferred

Published: 2026-08-31T16:18:35.370

Modified: 2026-09-01T17:17:30.440

Link: CVE-2026-51702

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-02T02:30:04Z

Weaknesses