Remote command execution in Zyxel CPE series devices

1) OS Command Injection

EUVDB-ID: #VU103459

Risk: High

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2024-40890

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: No

Description

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

The vulnerability exists due to improper input validation. A remote unauthenticated attacker can send specially crafted HTTP request to the affected device and execute arbitrary OS commands on the target system.

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

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Zyxel CPE Series: All versions

CPE2.3

• cpe:2.3:h:zyxel_communications_corp:zyxel_cpe_series:*:*:*:*:*:*:*:*

External links

https://viz.greynoise.io/tags/zyxel-cpe-cve-2024-40890-command-injection-attempt
https://www.greynoise.io/blog/active-exploitation-of-zero-day-zyxel-cpe-vulnerability-cve-2024-40891

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.