Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-51679 – Unauthenticated Admin Account Takeover – TOTOLINK T6 (Firmware 4.1.5cu.748_B2021101

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-51679 is a critical improper access control vulnerability (CWE-284) in the setPasswordCfg function of the TOTOLINK T6 web management interface, firmware version 4.1.5cu.748_B20211015. It allows an unauthenticated, remote attacker to change the router’s administrator account by sending a crafted POST request to /cgi-bin/cstecgi.cgi. The issue carries a CVSS v3.1 base score of 9.1 (Critical).

Technical details

  • Root cause: the setPasswordCfg handler in the device’s CGI application (cstecgi.cgi) does not enforce authentication or session validation before processing administrator credential-change requests.
  • Trigger condition: an attacker sends a specially crafted HTTP POST request to /cgi-bin/cstecgi.cgi targeting the setPasswordCfg function.
  • Attack vector: network-based, no authentication or user interaction required (AV:N/AC:L/PR:N/UI:N).
  • Impact: full compromise of the administrator account, giving the attacker complete control over the router’s configuration (high confidentiality and availability impact per the published vector).

Affected software

  • TOTOLINK T6, firmware version 4.1.5cu.748_B20211015

Severity

  • CVSS v3.1 Base Score: 9.1 (Critical)
  • Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Mitigation and recommended actions

  • Immediate: Check the TOTOLINK support/download portal for a firmware update addressing this issue for the T6 model and apply it as soon as it is available.
  • If no patch is available: Restrict access to the router’s web management interface so it is not reachable from the public internet; only allow administration from trusted internal networks or via VPN. Disable remote/WAN administration if enabled, and monitor for unexpected changes to administrator credentials.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge