Zyxel USG1100 Firmware vulnerabilities

6 CVEs affecting Zyxel USG1100 Firmware, 2 known to be exploited (CISA KEV), with EPSS scores. Latest: CVE-2021-35029, published 2021-07-02.

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-2019-12583, published 2019-06-27. Critical severity, CVSS 9.1. EPSS: 43.9% chance of exploitation in the next 30 days. Missing Access Control in the "Free Time" component of several Zyxel UAG, USG, and ZyWall devices allows a remote attacker to generate guest accounts by directly accessing the account generator. This…
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-2019-12581, published 2019-06-27. Medium severity, CVSS 6.1. EPSS: 6.4% chance of exploitation in the next 30 days. A reflective Cross-site scripting (XSS) vulnerability in the free_time_failed.cgi CGI program in selected Zyxel ZyWall, USG, and UAG devices allows remote attackers to inject arbitrary web script or…
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…