Multiple vulnerabilities in Zyxel NAS products

Published: 2020-08-05

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2020-13364 CVE-2020-13365
CWE-ID	CWE-284
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Zyxel NAS 326 Hardware solutions / Firmware NAS520 Hardware solutions / Routers for home users NAS540 Hardware solutions / Routers for home users NAS542 Hardware solutions / Routers for home users
Vendor	ZyXEL Communications Corp.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper access control

EUVDB-ID: #VU34061

Risk: Medium

CVSSv4.0: 6.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-13364

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

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

The vulnerability exists due to improper access restrictions in a CGI script for the web application. A remote authenticated attacker can start a Telnet or SSH service and generate a password for the "NsaRescueAngel" user account with root privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Zyxel NAS 326: before V5.21(AAZF.9)C0

NAS520: before V5.21(AASZ.5)C0

NAS540: before V5.21(AATB.6)C0

NAS542: before V5.21(ABAG.6)C0

CPE2.3

External links

http://www.zyxel.com/support/Zyxel-security-advisory-for-NAS-remote-access-vulnerability.shtml

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.

2) Improper access control

EUVDB-ID: #VU34062