Zyxel: Security Vulnerabilities
A null pointer dereference vulnerability in the certificate downloader CGI program of the Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.6)C0 and the Zyxel WX3100-T0 firmware versions through 5.50(ABVL.4.8)C0 could allow an authenticated attacker with administrator privileges to trigger a denial-of-service (DoS) condition by sending a crafted HTTP request.
CVSS Score
4.9
EPSS Score
0.008
Published
2026-02-24
An uncontrolled resource consumption vulnerability in the web server of Zyxel DX3301-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an attacker to perform Slowloris‑style denial‑of‑service (DoS) attacks. Such attacks may temporarily block legitimate HTTP requests and partially disrupt access to the web management interface, while other networking services remain unaffected.
CVSS Score
5.3
EPSS Score
0.003
Published
2025-11-18
A post-authentication command injection vulnerability in the "priv" parameter of Zyxel DX3300-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an authenticated attacker to execute operating system (OS) commands on an affected device.
CVSS Score
8.8
EPSS Score
0.01
Published
2025-11-18
A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow a semi-authenticated attacker—who has completed only the first stage of the two-factor authentication (2FA) process—to view and download the system configuration from an affected device.
CVSS Score
8.1
EPSS Score
0.051
Published
2025-10-21
A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow an authenticated attacker with administrator privileges to execute operating system (OS) commands on the affected device by passing a crafted string as an argument to a CLI command.
CVSS Score
7.2
EPSS Score
0.014
Published
2025-10-21
A buffer overflow vulnerability in the URL parser of the zhttpd web server in Zyxel VMG8825-T50K firmware versions prior to V5.50(ABOM.5)C0 could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and potentially execute arbitrary code by sending a specially crafted HTTP request.
CVSS Score
9.8
EPSS Score
0.005
Published
2025-07-16
A path traversal vulnerability in the file_upload-cgi CGI program of Zyxel NWA50AX PRO firmware version 7.10(ACGE.2) and earlier could allow an authenticated attacker with administrator privileges to access specific directories and delete files, such as the configuration file, on the affected device.
CVSS Score
7.2
EPSS Score
0.005
Published
2025-07-15
An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the Linux shell and escalate their privileges by crafting malicious scripts or modifying system configurations with administrator-level access through a stolen token. Modifying the system configuration is only possible if the administrator has not logged out and the token remains valid.
CVSS Score
7.8
EPSS Score
0.009
Published
2025-04-22
An improper privilege management vulnerability in the recovery function of the Zyxel USG FLEX H series uOS firmware version V1.31 and earlier could allow an authenticated local attacker with administrator privileges to upload a crafted configuration file and escalate privileges on a vulnerable device.
CVSS Score
6.7
EPSS Score
0.002
Published
2025-04-22
**UNSUPPORTED WHEN ASSIGNED** A path traversal vulnerability in the web management interface of the Zyxel AMG1302-T10B firmware version 2.00(AAJC.16)C0 could allow an authenticated attacker with administrator privileges to access restricted directories by sending a crafted HTTP request to an affected device.
CVSS Score
4.9
EPSS Score
0.083
Published
2025-04-22