FalehSec Exploited-vulnerability triage · joined from CISA KEV, NVD CVSS and EPSS

CVE-2024-40891

Zyxel · DSL CPE Devices · Zyxel DSL CPE OS Command Injection Vulnerability

Verdict
Patch soon · actively exploited, not reachable unauthenticated from the internet, and in the top 5% of CVEs by near-term exploitation probability

Added to CISA KEV 2025-02-11 · exploited in the wild for 593 days

What an attacker can reach How likely Time What CISA says to do Sources All 545

What an attacker can reach

CVSS 8.8 HIGH. The score is a summary; these three components are the part that decides whether something scanning the internet can use it.

Attack vectornetworkreachable over the network, with no local access needed
Privileges requiredlowneeds some credentials, so a fully anonymous attacker cannot reach it directly
User interactionnonecan be triggered with nobody interacting with the page or request
Base vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
WeaknessCWE-78

This describes the vulnerability. It says nothing about whether your systems run it.

How likely

EPSS puts the probability of exploitation in the next 30 days at 0.2154, which places it in the top 5% of all tracked CVEs. The percentile is the more useful half: 0.18 in absolute terms sounds low until you know most of the internet-facing software in the world scores under that.

EPSS probability0.2154
Percentile0.975 — top 5%

Time

Added to KEV2025-02-11
Days exploited593
Federal remediation duenot set
Ransomware useno known ransomware campaign use

What CISA says to do

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.

**UNSUPPORTED WHEN ASSIGNED** A post-authentication command injection vulnerability in the management commands of the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an authenticated attacker to execute operating system (OS) commands on an affected device via Telnet.

Sources