Cyber Posture

CVE-2026-5101

MediumPublic PoC

Published: 29 March 2026

Published
29 March 2026
Modified
30 March 2026
KEV Added
Patch
CVSS Score 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0362 87.9th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Description

A vulnerability was identified in Totolink A3300R 17.0.0cu.557_b20221024. This affects the function setLanCfg of the file /cgi-bin/cstecgi.cgi of the component Parameter Handler. The manipulation of the argument lanIp leads to command injection. Remote exploitation of the attack is possible. The…

more

exploit is publicly available and might be used.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly prevents command injection by validating the lanIp parameter in the setLanCfg function to block malicious input.

prevent

Mitigates the vulnerability through timely flaw remediation by patching the affected Totolink A3300R firmware.

detect

Enables detection of command injection attempts via monitoring for anomalous network connections and privileged events on the router.

Security SummaryAI

CVE-2026-5101 is a command injection vulnerability affecting the Totolink A3300R router on firmware version 17.0.0cu.557_b20221024. The issue resides in the setLanCfg function of the /cgi-bin/cstecgi.cgi file within the Parameter Handler component, where manipulation of the lanIp argument triggers command injection. Published on 2026-03-29, it is associated with CWEs-74, CWE-77, and CWE-78, and carries a CVSS v3.1 base score of 6.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L).

Remote attackers with low privileges can exploit this vulnerability over the network with low complexity and no user interaction required. Exploitation enables arbitrary command execution, potentially leading to low impacts on confidentiality, integrity, and availability, such as limited data access, modification, or disruption on the affected device. A public exploit is available, increasing the risk of widespread use.

Advisories referenced in VULDB entries (vuln/354126 and related CTI) document the vulnerability details and submission, while a GitHub repository provides exploit code and a README. The Totolink vendor website is listed for potential firmware updates or mitigation guidance. Security practitioners should verify patches directly from these sources.

Details

CWE(s)

Affected Products

totolink
a3300r firmware
17.0.0cu.557_b20221024

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.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

Command injection in public-facing web CGI interface (setLanCfg via lanIp) enables exploitation of public-facing application (T1190) and arbitrary Unix shell command execution on the router (T1059.004).

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

References