CVE-2026-75121

Received Received - Intake

Authenticated OS Command Injection in PLANET GS-4210-16P2S Firmware

Publication date: 2026-08-28

Last updated on: 2026-08-28

Assigner: VulnCheck

Description

PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/dispatcher.cgi. The web_vlan_membership_edit_dialog_post handler incorporates the memberTags POST parameter into a shell command without sanitization. A remote authenticated attacker can send a crafted memberTags value to execute arbitrary operating-system commands on the device.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-28

Last Modified

2026-08-28

Generated

2026-08-29

AI Q&A

2026-08-29

EPSS Evaluated

N/A

NVD

CVE-2026-75121

EUVD

EUVD-2026-67781

Affected Vendors & Products

Vendor	Product	Version / Range
planet	gs-4210-16p2s	to 3.441b260626 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-78	The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Attack-Flow Graph

Executive Summary

This vulnerability is an authenticated OS command injection flaw in the PLANET GS-4210-16P2S firmware versions before 3.441b260626. It exists in the /cgi-bin/dispatcher.cgi file, specifically in the web_vlan_membership_edit_dialog_post handler. The issue arises because the memberTags POST parameter is directly incorporated into a shell command without proper sanitization, allowing remote authenticated attackers to inject and execute arbitrary operating system commands on the device.

Detection Guidance

Detect this vulnerability by checking the firmware version of PLANET GS-4210-16P2S devices. If the firmware is before version 3.441b260626, the device is vulnerable. Logs may show unusual commands executed via /cgi-bin/dispatcher.cgi with crafted memberTags parameters.

Impact Analysis

This vulnerability allows remote authenticated attackers to execute arbitrary commands on the affected device. This could lead to unauthorized access, data manipulation, or disruption of network services. Attackers might gain control over the device, steal sensitive information, or use it as a pivot point to compromise other systems in the network.

Compliance Impact

This vulnerability could lead to unauthorized access and data breaches, which may violate compliance requirements under GDPR, HIPAA, and other regulations. Organizations using the affected device may face legal penalties, reputational damage, and loss of customer trust due to potential exposure of sensitive data.

Mitigation Strategies

Immediately update the firmware of all PLANET GS-4210-16P2S devices to version 3.441b260626 or later. Restrict access to the web interface to trusted networks or IP addresses. Monitor network traffic for suspicious activity targeting /cgi-bin/dispatcher.cgi.

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