Cyber Posture

CVE-2026-6131

Critical

Published: 12 April 2026

Published
12 April 2026
Modified
27 April 2026
KEV Added
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Patch
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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0125 79.5th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

A vulnerability was found in Totolink A7100RU 7.4cu.2313_b20191024. Affected by this vulnerability is the function setTracerouteCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument command results in os command injection. The attack may be…

more

launched remotely. The exploit has been made public and could be used.

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match
prevent

Directly prevents OS command injection by validating and sanitizing the untrusted 'command' argument in the setTracerouteCfg CGI function.

SI-2 Flaw Remediation good match
prevent

Remediates the specific command injection flaw in the Totolink A7100RU firmware through identification, reporting, and correction.

IA-8 Identification and Authentication (Non-organizational Users) good match
prevent

Blocks unauthenticated remote attackers from accessing and exploiting the vulnerable CGI handler endpoint.

Security SummaryAI

CVE-2026-6131 is an OS command injection vulnerability affecting the Totolink A7100RU router on firmware version 7.4cu.2313_b20191024. The flaw resides in the setTracerouteCfg function within the /cgi-bin/cstecgi.cgi file of the CGI Handler component, where manipulation of the "command" argument enables arbitrary OS command execution. Published on 2026-04-12, it is classified under CWE-77 (Command Injection) and CWE-78 (OS Command Injection).

The vulnerability carries a CVSS v3.1 base score of 9.8 (Critical) with the vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Any unauthenticated remote attacker can exploit it over the network with low complexity and no user interaction required, potentially achieving high impacts on confidentiality, integrity, and availability, such as full device compromise, data exfiltration, persistent access, or service disruption.

Advisories referenced in VulDB entries (vuln/356995 and related pages) document the issue, while a GitHub repository provides a public exploit at https://github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_182/README.md. The Totolink vendor site (https://www.totolink.net/) is listed, but no specific patches or mitigations are detailed in the available information.

The exploit has been publicly disclosed and could be used by attackers targeting exposed Totolink A7100RU devices.

Details

CWE(s)
CWE-77CWE-78

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

Unauthenticated remote OS command injection via public-facing web CGI interface directly enables T1190 (Exploit Public-Facing Application) and facilitates arbitrary Unix Shell execution (T1059.004) on the router.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References