SB2022052406 - Multiple vulnerabilities in Zyxel Firewalls, AP controllers and APs

Description

This security bulletin contains information about 4 vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2022-0734)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in the CGI program. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

2) Input validation error (CVE-ID: CVE-2022-26531)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in some CLI commands. A local user can pass specially crafted input to the application and perform a denial of service (DoS) attack.

3) OS Command Injection (CVE-ID: CVE-2022-26532)

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

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation in the "packet-trace" CLI command. A local 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.

4) Improper access control (CVE-ID: CVE-2022-0910)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 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:U/U:Amber

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions in the CGI program. A remote attacker can downgrade from two-factor authentication to one-factor authentication via an IPsec VPN client.

Remediation

Install update from vendor's website.

References

• https://www.zyxel.com/support/multiple-vulnerabilities-of-firewalls-AP-controllers-and-APs.shtml