Cyber Resilience

CVE-2026-31170

CriticalPublic PoCRCE

Published: 09 April 2026

Published
09 April 2026
Modified
22 April 2026
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0057 42.9th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-31170 is a critical-severity Command Injection (CWE-77) vulnerability in Totolink A3300R Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 42.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-31170 is a command injection vulnerability (CWE-77) in ToToLink A3300R firmware version v17.0.0cu.557_B20221024. The issue resides in the /cgi-bin/cstecgi.cgi component, where the stun-pass parameter can be manipulated by attackers to execute arbitrary commands on the device.

With a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), the vulnerability is critically severe and exploitable remotely over the network with low complexity. Unauthenticated attackers require no privileges or user interaction to trigger it, potentially achieving high-impact compromise of confidentiality, integrity, and availability through arbitrary command execution.

References point to GitHub repositories at https://github.com/Svigo-o/TOTOLINK-Vul/tree/main/totolink-a3300r-stun-pass-cmd-injection, which contain proof-of-concept details for the stun-pass command injection in ToToLink A3300R. No vendor advisories or patches are specified in the available information.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

An issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbitrary commands via the stun-pass parameter to /cgi-bin/cstecgi.cgi.

CWE(s)
CWE-77

Related Threats

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 command injection via public-facing web CGI (T1190: Exploit Public-Facing Application) enables arbitrary Unix shell command execution on the router firmware (T1059.004: Unix Shell).

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

CVEs Like This One

CVE-2026-31175Same product: Totolink A3300R
CVE-2026-5177Same product: Totolink A3300R
CVE-2026-5104Same product: Totolink A3300R
CVE-2026-5102Same product: Totolink A3300R
CVE-2026-5103Same product: Totolink A3300R
CVE-2026-5101Same product: Totolink A3300R
CVE-2025-52046Same product: Totolink A3300R
CVE-2026-5105Same product: Totolink A3300R
CVE-2026-5176Same product: Totolink A3300R
CVE-2026-5178Same product: Totolink A3300R

Affected Assets

totolink
a3300r firmware
17.0.0cu.557_b20221024

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly prevents command injection by requiring validation and sanitization of inputs like the stun-pass parameter in the cstecgi.cgi script.

SI-2 Flaw Remediation good match
prevent

Requires timely identification, reporting, and patching of the specific command injection flaw in the ToToLink A3300R firmware.

AC-6 Least Privilege partial match
prevent

Limits the impact of successful command injection by enforcing least privilege on processes handling the vulnerable stun-pass parameter.

References