Zyxel USG20-VPN Firmware vulnerabilities

15 CVEs affecting Zyxel USG20-VPN Firmware, 4 known to be exploited (CISA KEV), with EPSS scores. Latest: CVE-2023-6764, published 2024-02-20.

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-2020-29583: Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability, published 2020-12-22. Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 90.2% chance of exploitation in the next 30 days. Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. The password for this account can be found in cleartext in the firmware. This…
CVE-2023-33010: Zyxel Multiple Firewalls Buffer Overflow Vulnerability, published 2023-05-24. Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2023-06-05. EPSS: 29% chance of exploitation in the next 30 days. A buffer overflow vulnerability in the ID processing function in Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1, USG FLEX series firmware versions 4.50 through 5.36 Patch 1, USG FLEX…
CVE-2023-33009: Zyxel Multiple Firewalls Buffer Overflow Vulnerability, published 2023-05-24. Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2023-06-05. EPSS: 28.1% chance of exploitation in the next 30 days. A buffer overflow vulnerability in the notification function in Zyxel ATP series firmware versions 4.60 through 5.36 Patch 1, USG FLEX series firmware versions 4.60 through 5.36 Patch 1, USG FLEX…
CVE-2019-9955, published 2019-04-22. Medium severity, CVSS 6.1. EPSS: 21.2% chance of exploitation in the next 30 days. On Zyxel ATP200, ATP500, ATP800, USG20-VPN, USG20W-VPN, USG40, USG40W, USG60, USG60W, USG110, USG210, USG310, USG1100, USG1900, USG2200-VPN, ZyWALL 110, ZyWALL 310, ZyWALL 1100 devices, the security…
CVE-2022-38547, published 2023-02-07. High severity, CVSS 7.2. EPSS: 2.8% chance of exploitation in the next 30 days. A post-authentication command injection vulnerability in the CLI command of Zyxel ZyWALL/USG series firmware versions 4.20 through 4.72, VPN series firmware versions 4.30 through 5.32, USG FLEX…
CVE-2021-35029, published 2021-07-02. Critical severity, CVSS 9.8. EPSS: 2.3% chance of exploitation in the next 30 days. An authentication bypasss vulnerability in the web-based management interface of Zyxel USG/Zywall series firmware versions 4.35 through 4.64 and USG Flex, ATP, and VPN series firmware versions 4.35…
CVE-2023-27991, published 2023-04-24. High severity, CVSS 8.8. EPSS: 1.5% chance of exploitation in the next 30 days. The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W)…
CVE-2022-2030, published 2022-07-19. Medium severity, CVSS 6.5. EPSS: 1.4% chance of exploitation in the next 30 days. A directory traversal vulnerability caused by specific character sequences within an improperly sanitized URL was identified in some CGI programs of Zyxel USG FLEX 100(W) firmware versions 4.50…
CVE-2023-6398, published 2024-02-20. High severity, CVSS 7.2. EPSS: 1.3% chance of exploitation in the next 30 days. A post-authentication command injection vulnerability in the file upload binary in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50…

Latest

CVE-2023-6764, published 2024-02-20. High severity, CVSS 8.1. EPSS: 0.9% chance of exploitation in the next 30 days. A format string vulnerability in a function of the IPSec VPN feature in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50…
CVE-2023-6399, published 2024-02-20. Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days. A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware…
CVE-2023-27990, published 2023-04-24. Medium severity, CVSS 4.8. EPSS: 0.3% chance of exploitation in the next 30 days. The cross-site scripting (XSS) vulnerability in Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16…
CVE-2023-22918, published 2023-04-24. Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days. A post-authentication information exposure vulnerability in the CGI program of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX…
CVE-2022-30526, published 2022-07-19. High severity, CVSS 7.8. EPSS: 1.1% chance of exploitation in the next 30 days. A privilege escalation vulnerability was identified in the CLI command of Zyxel USG FLEX 100(W) firmware versions 4.50 through 5.30, USG FLEX 200 firmware versions 4.50 through 5.30, USG FLEX 500…