OS Command Injection in Zyxel firewalls

1) OS Command Injection

EUVDB-ID: #VU71972

Risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-38547

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 user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ATP series: 4.32 - 5.32

USG FLEX series: 4.50 - 5.32

VPN series: 4.30 - 5.32

ZyWALL: 4.20 - 4.72

USG series: 4.20 - 4.72

CPE2.3

• cpe:2.3:h:zyxel_communications_corp:atp_series:4.32:*:*:*:*:*:*:*
• cpe:2.3:h:zyxel_communications_corp:atp_series:*:*:*:*:*:*:*:*
• cpe:2.3:h:zyxel_communications_corp:atp_series:5.32:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_flex_series:4.50:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_flex_series:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_flex_series:5.32:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:vpn_series:4.30:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:vpn_series:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:vpn_series:5.32:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:zywall:4.20:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:zywall:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:zywall:4.72:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_series:4.20:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_series:*:*:*:*:*:*:*:*
• cpe:2.3:a:zyxel_communications_corp:usg_series:4.72:*:*:*:*:*:*:*

External links

http://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-post-authentication-rce-in-firewalls

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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?

No. We are not aware of malware exploiting this vulnerability.