CVE-2024-40891
Zyxel DSL CPE OS Command Injection Vulnerability
Zyxel DSL CPE Devices
**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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 11 February 2025. US federal agencies were required to remediate it by 4 March 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 22.9%, which is higher than 97.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2024-40891 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2024-40891.
What does CVE-2024-40891 affect?
CVE-2024-40891 affects Zyxel DSL CPE Devices. **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.
How severe is CVE-2024-40891?
CVE-2024-40891 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 22.9%, higher than 97.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 4 March 2025.
How should organisations respond to CVE-2024-40891?
Apply the vendor patch for Zyxel DSL CPE Devices as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.