SB2024022031 - Multiple vulnerabilities in Zyxel firewalls and APs

Description

This security bulletin contains information about 4 vulnerabilities.

1) NULL pointer dereference (CVE-ID: CVE-2023-6397)

CWE-ID: CWE-476 - NULL Pointer Dereference

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

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error. A remote attacker on the local network can use a specially crafted RAR compressed file and perform a denial of service (DoS) attack.

2) Format string error (CVE-ID: CVE-2023-6399)

CWE-ID: CWE-134 - Use of Externally-Controlled Format String

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

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a format string error. A remote user on the local network can supply a specially crafted input that contains format string specifiers and cause a denial of service condition on the target system.

3) Format string error (CVE-ID: CVE-2023-6764)

CWE-ID: CWE-134 - Use of Externally-Controlled Format String

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 execute arbitrary code on the target system.

The vulnerability exists due to a format string error in a function of the IPSec VPN feature. A remote attacker can supply a specially crafted input that contains format string specifiers and execute arbitrary code on the target system.

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

4) OS Command Injection (CVE-ID: CVE-2023-6398)

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

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

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

The vulnerability exists due to improper input validation in the file upload binary. A remote administrator 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.

Remediation

Install update from vendor's website.

References

• https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024