---
id: "CVE-2024-40890"
kind: "vulnerability"
aliases: ["CVE-2024-40890"]
title: "**UNSUPPORTED WHEN ASSIGNED** A post-authentication command injection vulnerability in the CGI program of the legacy\u2026"
severity: "high"
cvss: 8.8
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Zyxel DSL CPE Devices", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg1312-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg1312-b10b firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg1312-b10e firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg3312-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg3313-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg3926-b10b firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg4325-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg4380-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg8324-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel vmg8924-b10a firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel sbg3300-n000 firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel sbg3300-nb00 firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel sbg3500-n000 firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "zyxel sbg3500-nb00 firmware", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["dsl-cpe", "exploited", "infrastructure", "isp-equipment", "routers", "zyxel"]
not_affected_if: ["managed-hosting", "no-zyxel-dsl-devices"]
published_at: "2025-02-04T10:15:08+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:05+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2024-40890", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40890", "first_seen_at": "2026-10-23T22:29:05+00:00"}]
---

# **UNSUPPORTED WHEN ASSIGNED** A post-authentication command injection vulnerability in the CGI program of the legacy…

Multiple Zyxel DSL CPE devices have an OS command injection flaw in a CGI program that lets an authenticated user run commands on the device through a crafted HTTP request. CISA lists it as actively exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Zyxel DSL CPE Devices affected ? fixed ?
- vendor:zyxel vmg1312-b10a firmware affected ? fixed ?
- vendor:zyxel vmg1312-b10b firmware affected ? fixed ?
- vendor:zyxel vmg1312-b10e firmware affected ? fixed ?
- vendor:zyxel vmg3312-b10a firmware affected ? fixed ?
- vendor:zyxel vmg3313-b10a firmware affected ? fixed ?
- vendor:zyxel vmg3926-b10b firmware affected ? fixed ?
- vendor:zyxel vmg4325-b10a firmware affected ? fixed ?
- vendor:zyxel vmg4380-b10a firmware affected ? fixed ?
- vendor:zyxel vmg8324-b10a firmware affected ? fixed ?
- vendor:zyxel vmg8924-b10a firmware affected ? fixed ?
- vendor:zyxel sbg3300-n000 firmware affected ? fixed ?
- vendor:zyxel sbg3300-nb00 firmware affected ? fixed ?
- vendor:zyxel sbg3500-n000 firmware affected ? fixed ?
- vendor:zyxel sbg3500-nb00 firmware affected ? fixed ?

## How to check

Identify Zyxel DSL CPE models in your estate and compare them against the affected product list in the vendor advisory; unknown whether the sources give a firmware version check.

## Fix

Apply the vendor's patched firmware if one exists for your model.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2024-40890
- 2026-10-23T22:29:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2024-40890

## From the sources

Multiple Zyxel DSL CPE devices contain a post-authentication command injection vulnerability in the CGI program that could allow an authenticated attacker to execute OS commands via a crafted HTTP request.

CISA required action: The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization if a current mitigation is unavailable.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_