Skip to main content

TOTOLINK T6 CVE-2026-51647

| EUVDEUVD-2026-67919 HIGH
Improper Access Control (CWE-284)
2026-08-28 mitre GHSA-79gx-m5qg-8x23
7.5
CVSS 3.1 · Vendor: mitre
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Reach router HTTP management interface
  2. Delivery
    Send unauthenticated POST to /cgi-bin/cstecgi.cgi
  3. Exploit
    Invoke getCrpcCfg without access control check
  4. Execution
    Receive CRPC status and cloud URL
  5. Impact
    Target cloud management endpoint

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK

1 technique across 1 tactic: Defense Evasion

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

No authentication is required to trigger this vulnerability - the CVSS vector PR:N confirms unauthenticated access. The attack requires network reachability to the router's HTTP management interface on /cgi-bin/cstecgi.cgi. In default TOTOLINK T6 configurations, the management interface is typically accessible only from the LAN side, which limits exploitation to local network attackers or devices already on the same subnet. If WAN-side remote management has been enabled by the user (a non-default setting on most SOHO routers), exploitation becomes possible from the internet without any credentials. The affected firmware version must be 4.1.5cu.748_B20211015; other firmware versions are not confirmed as affected.

Impact

The CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N rates this 7.5, but C:H overstates the sensitivity of the disclosed data - the leak is limited to cloud remote-control enablement status and a management URL, not credentials, session tokens, or full configuration. A more accurate independent assessment places this at C:L, yielding a score closer to 5.3. EPSS at 0.18% (7th percentile) confirms no meaningful automated exploitation activity. The vulnerability is not listed in CISA KEV. GitHub-hosted CVE coordination repositories (DarkBoulder, ShengWu00) reference this issue, indicating researcher awareness and potential for POC development, though no confirmed working exploit code is identified. Real-world risk is further bounded by the product's consumer SOHO footprint and the typical LAN-only exposure of the management interface on most default configurations.

Exploit ScenarioDerived

An attacker on the same local network - or with WAN management access enabled - sends a crafted HTTP POST request to http://[router-ip]/cgi-bin/cstecgi.cgi invoking the getCrpcCfg action. The router responds without requiring authentication, returning the CRPC status flag and cloud management URL. The attacker now knows whether cloud remote management is active and can target the cloud endpoint for further reconnaissance or abuse.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.2% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Sep 01, 2026

Unauthenticated information disclosure in TOTOLINK T6 firmware 4.1.5cu.748_B20211015 exposes cloud remote-control (CRPC) status and management URL through the getCrpcCfg function. The /cgi-bin/cstecgi.cgi endpoint processes POST requests without enforcing access control, allowing any network-adjacent attacker to enumerate whether cloud remote management is active and retrieve its target URL. No public exploit has been identified at time of analysis and EPSS sits at the 7th percentile, indicating low current exploitation pressure despite the trivially simple attack vector.

RemediationAI

No vendor-released patch with a confirmed fix version has been identified at time of analysis. The TOTOLINK download page is referenced but does not specify a remediated firmware release. As a compensating control, administrators should restrict access to the router's management interface (port 80/443 on the LAN interface) using firewall rules or VLAN segmentation so that only trusted management hosts can reach /cgi-bin/cstecgi.cgi - this reduces the attack surface without disabling the device. Additionally, disabling cloud remote-control (CRPC) functionality in the router settings, if exposed through the UI, removes the value of the leaked data entirely. Monitor the TOTOLINK firmware download page (https://www.totolink.net/) for updated firmware releases.

Affected VersionsENISA

n/a n/a

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

TOTOLINK T6 is a consumer/SOHO wireless router running a CGI-based management interface at /cgi-bin/cstecgi.cgi. The getCrpcCfg function handles retrieval of Cloud Remote PC Control (CRPC) configuration, including the cloud management status flag and the URL of the cloud endpoint. CWE-284 (Improper Access Control) indicates the function lacks any authentication gate - it processes the POST request and returns configuration data without checking session tokens, credentials, or source IP restrictions. The affected firmware version is 4.1.5cu.748_B20211015. CPE data in the input uses the placeholder cpe:2.3:a:n/a:n/a which is incorrect; the correct product is totolink:t6_firmware.

Know when TOTOLINK gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (mitre) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vuln.today AI 5.3 MEDIUM

Disclosed data is limited to CRPC status and cloud URL - not credentials or full config - so C:H overstates impact; C:L is appropriate.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (mitre).

CVSS VectorVendor: mitre

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Lifecycle Timeline

3
CVSS changed
Sep 01, 2026 - 17:22 NVD
7.5 (HIGH)
CVE Published
Aug 28, 2026 - 00:00 cve.org
UNKNOWN (no severity yet)
CVE Published
Aug 28, 2026 - 00:00 cve.org
HIGH 7.5

DescriptionCVE.org

Incorrect access control in the getCrpcCfg function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to obtain cloud remote-control status and URL information via sending a crafted POST request to /cgi-bin/cstecgi.cgi.

Executive ViewAI

Why It Matters

TOTOLINK T6 routers expose cloud remote-control configuration to any network-adjacent attacker without authentication, revealing whether remote management is active and its target URL. Organizations relying on these routers for branch or WAN connectivity face reconnaissance risk that could facilitate targeted attacks against remote access infrastructure. While no public exploit currently identified, the trivially exploitable nature and lack of vendor remediation create urgent need for interim controls.

Business Impact: Medium
Compensating Controls

No vendor-released patch identified at time of analysis. Disable CRPC functionality if not required for operations; implement network-layer access controls (firewall filtering, VLAN segmentation) to restrict /cgi-bin/cstecgi.cgi access from untrusted sources; monitor router access logs for unexpected getCrpcCfg requests.

Threat Intelligence Overview

EPSS Score
0.2%
Top 93% exploitable
Prevalence
Low
consumer SOHO router, limited enterprise or large-scale deployment
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
Medium
Technical Impact
Partial

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

CVE-2025-52053 CRITICAL POC
9.8 Sep 15

TOTOLINK X6000R router firmware V9.4.0cu.1360_B20241207 contains an unauthenticated command injection in the sub_417D74

CVE-2023-52028 CRITICAL POC
9.8 Jan 11

TOTOlink A3700R v9.1.2u.5822_B20200513 was discovered to contain a remote command execution (RCE) vulnerability via the

CVE-2025-25579 CRITICAL POC
9.8 Mar 28

TOTOLINK A3002R V4.0.0-B20230531.1404 is vulnerable to Command Injection in /bin/boa via bandstr. Rated critical severit

CVE-2023-52032 CRITICAL POC
9.8 Jan 11

TOTOlink EX1200T V4.1.2cu.5232_B20210713 was discovered to contain a remote command execution (RCE) vulnerability via th

CVE-2023-52029 CRITICAL POC
9.8 Jan 11

TOTOlink A3700R v9.1.2u.5822_B20200513 was discovered to contain a remote command execution (RCE) vulnerability via the

CVE-2023-52027 CRITICAL POC
9.8 Jan 11

TOTOlink A3700R v9.1.2u.5822_B20200513 was discovered to contain a remote command execution (RCE) vulnerability via the

CVE-2025-45858 CRITICAL POC
9.8 May 13

TOTOLINK A3002R v4.0.0-B20230531.1404 was discovered to contain a command injection vulnerability via the FUN_00459fdc f

CVE-2021-46009 CRITICAL POC
9.8 Mar 30

In Totolink A3100R V5.9c.4577, multiple pages can be read by curl or Burp Suite without authentication. Rated critical s

CVE-2023-30013 CRITICAL POC
9.8 May 05

TOTOLINK X5000R V9.1.0u.6118_B20201102 and V9.1.0u.6369_B20230113 contain a command insertion vulnerability in setting/s

CVE-2023-52031 CRITICAL POC
9.8 Jan 11

TOTOlink A3700R v9.1.2u.5822_B20200513 was discovered to contain a remote command execution (RCE) vulnerability via the

CVE-2023-52030 CRITICAL POC
9.8 Jan 11

TOTOlink A3700R v9.1.2u.5822_B20200513 was discovered to contain a remote command execution (RCE) vulnerability via the

CVE-2025-28137 CRITICAL POC
9.8 Apr 15

The TOTOLINK A810R V4.1.2cu.5182_B20201026 were found to contain a pre-auth remote command execution vulnerability in th

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy