CVE-2026-51739
Deferred Deferred - Pending Action

Incorrect Access Control in TOTOLINK T6 Firmware

Publication date: 2026-08-31

Last updated on: 2026-08-31

Assigner: MITRE

Description
Incorrect access control in the CloudSrvVersionCheck function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to trigger cloud update checks via sending a crafted POST request to /cgi-bin/cstecgi.cgi.

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Meta Information

Published
2026-08-31
Last Modified
2026-08-31
Generated
2026-09-01
AI Q&A
2026-08-31
EPSS Evaluated
N/A
NVD
CVE-2026-51739
EUVD
EUVD-2026-68742

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
totolink t6 4.1.5cu.748_b20211015

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability is an incorrect access control issue in the CloudSrvVersionCheck function of TOTOLINK T6 firmware version 4.1.5cu.748_B20211015. It allows unauthenticated attackers to force the device to perform cloud update checks by sending a specially crafted POST request to /cgi-bin/cstecgi.cgi.

Detection Guidance

To detect this vulnerability, monitor network traffic for POST requests to /cgi-bin/cstecgi.cgi with parameters triggering the CloudSrvVersionCheck function. Check server logs for unauthorized access attempts or unusual update requests.

Impact Analysis

An attacker could exploit this to trigger unnecessary or malicious cloud update checks on the device. This might lead to information disclosure, denial of service, or potential remote code execution if the update process is compromised.

Compliance Impact

This vulnerability allows unauthenticated attackers to trigger cloud update checks via crafted POST requests, which could lead to unauthorized access or control of the device. Such access could compromise data integrity and confidentiality, potentially violating compliance requirements under GDPR (data protection) and HIPAA (healthcare data security) if sensitive information is exposed or altered.

Mitigation Strategies

Immediately restrict access to /cgi-bin/cstecgi.cgi via firewall rules. Update the TOTOLINK T6 firmware to the latest patched version if available. Disable unnecessary services and monitor for suspicious activity.

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