Zero-day vulnerability in Zyxel CPE Series

Command Injection
CVE-2024-40891

Not patched

Vulnerability details

Advisory: SB2025013026 - Remote command injection in Zyxel CPE Series

Vulnerable component: Zyxel CPE Series

CVE-ID: CVE-2024-40891

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:A/RL:U/RC:C

CWE-ID: CWE-77 - Command injection

Description:

The vulnerability allows a remote attacker to execute arbitrary commands on the target system.

The vulnerability exists due to improper input validation. A remote unauthenticated attacker can send specially crafted packets to the telnet interface of a device and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, the vulnerability is being actively exploited in the wild.

External links:

https://www.greynoise.io/blog/active-exploitation-of-zero-day-zyxel-cpe-vulnerability-cve-2024-40891

https://www.helpnetsecurity.com/2025/01/29/zyxel-cpe-devices-under-attack-vulnerability-cve-2024-40891/