Zyxel NAS540 Firmware vulnerabilities

5 CVEs affecting Zyxel NAS540 Firmware, 2 known to be exploited (CISA KEV), with EPSS scores. Latest: CVE-2023-27992, published 2023-06-19.

Highest priority

Known exploited (CISA KEV) first, then by EPSS exploit probability.

CVE-2020-9054: Zyxel Multiple NAS Devices OS Command Injection Vulnerability, published 2020-03-04. Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-03-25. EPSS: 100% chance of exploitation in the next 30 days. Multiple ZyXEL network-attached storage (NAS) devices running firmware version 5.21 contain a pre-authentication command injection vulnerability, which may allow a remote, unauthenticated attacker to…
CVE-2023-27992: Zyxel Multiple NAS Devices Command Injection Vulnerability, published 2023-06-19. Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2023-06-23. EPSS: 82.8% chance of exploitation in the next 30 days. The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware…
CVE-2023-27988, published 2023-05-30. High severity, CVSS 7.2. EPSS: 1.4% chance of exploitation in the next 30 days. The post-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.13)C0 could allow an authenticated attacker with administrator privileges to execute…
CVE-2020-13364, published 2020-08-06. High severity, CVSS 8.8. EPSS: 1.2% chance of exploitation in the next 30 days. A backdoor in certain Zyxel products allows remote TELNET access via a CGI script. This affects NAS520 V5.21(AASZ.4)C0, V5.21(AASZ.0)C0, V5.11(AASZ.3)C0, and V5.11(AASZ.0)C0; NAS542 V5.11(ABAG.0)C0,…
CVE-2020-13365, published 2020-08-06. High severity, CVSS 8.8. EPSS: 1% chance of exploitation in the next 30 days. Certain Zyxel products have a locally accessible binary that allows a non-root user to generate a password for an undocumented user account that can be used for a TELNET session as root. This affects…