#VU75462 Command Injection in USG FLEX series and VPN series - CVE-2023-22913

Vulnerability identifier: #VU75462

Vulnerability risk: Medium

CVSSv4.0: 6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-22913

CWE-ID: CWE-77

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
USG FLEX series
Client/Desktop applications / Antivirus software/Personal firewalls
VPN series
Client/Desktop applications / Antivirus software/Personal firewalls

Vendor: ZyXEL Communications Corp.

Description

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

The vulnerability exists due to improper input validation in the "account_operator.cgi" CGI program. A remote user can pass specially crafted data to the application and execute arbitrary 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

USG FLEX series: 4.50 - 5.35

VPN series: 4.30 - 5.35

---

External links
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-of-firewalls-and-aps

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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