Vulnerability · Published Apr 24, 2023 · Assigned by Zyxel

CVE-2023-27991

High 8.8

In plain English

A high-severity OS command injection in ATP series firmware from Zyxel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.5% (higher than 74% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)1.5%top 26.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.

Affected products (as reported)

Vendor	Product	Versions
Zyxel	ATP series firmware	4.32 through 5.35
Zyxel	USG FLEX series firmware	4.50 through 5.35
Zyxel	USG FLEX 50(W) firmware	4.16 through 5.35
Zyxel	USG20(W)-VPN firmware	4.16 through 5.35
Zyxel	VPN series firmware	4.30 through 5.35

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls