{"id":"CVE-2022-0342","published":"2022-03-28T12:05:11Z","modified":"2024-08-02T23:25:40Z","title":"An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through…","vendor":"Zyxel","product":"USG/ZyWALL series firmware","tier":"core","eol":null,"affectedVersions":[{"vendor":"Zyxel","product":"USG/ZyWALL series firmware","versions":["4.20 through 4.70"]},{"vendor":"Zyxel","product":"USG FLEX series firmware","versions":["4.50 through 5.20"]},{"vendor":"Zyxel","product":"ATP series firmware","versions":["4.32 through 5.20"]},{"vendor":"Zyxel","product":"VPN series firmware","versions":["4.30 through 5.20"]},{"vendor":"Zyxel","product":"NSG series firmware","versions":["1.20 through 1.33 Patch 4"]}],"description":{"text":"An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4.70, USG FLEX series firmware versions 4.50 through 5.20, ATP series firmware versions 4.32 through 5.20, VPN series firmware versions 4.30 through 5.20, and NSG series firmware versions V1.20 through V1.33 Patch 4, which could allow an attacker to bypass the web authentication and obtain administrative access of the device.","provenance":"source","from":"CVE.org"},"summary":{"text":"An authentication bypass in the CGI program of Zyxel USG/ZyWALL series firmware (along with the USG FLEX, ATP, VPN and NSG series firmware) lets an attacker circumvent web authentication on the device. The attacker needs only network access to the device's web interface, with no credentials or user interaction required, and can thereby obtain administrative access to the device.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:11:56Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.95134,"percentile":0.99863,"date":"2026-10-29","provenance":"source"},"kev":null,"vulncheckKev":{"dateAdded":"2025-10-17","exploitedFirstSeen":null,"ransomware":false,"evidence":[],"evidenceTotal":0,"provenance":"source"},"exploited":true,"otx":{"pulseCount":1,"pulses":[{"name":"Zyxel authentication bypass patch analysis (CVE-2022-0342) - hn security","url":"https://otx.alienvault.com/pulse/6368bb4b67766bb50b918376","created":"2022-11-07"}],"provenance":"machine"},"cwes":[{"id":"CWE-287","name":"Improper Authentication"}],"references":[{"url":"https://www.zyxel.com/support/Zyxel-security-advisory-for-authentication-bypass-vulnerability-of-firewalls.shtml","tags":["x_refsource_CONFIRM"]}],"techniques":[],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2022-15502","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2022-15502","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":{"nuclei":[{"id":"CVE-2022-0342","name":"Zyxel - Authentication Bypass","severity":"critical","path":"http/cves/2022/CVE-2022-0342.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2022/CVE-2022-0342.yaml"}],"provenance":"source"},"exploitRefs":[],"flow":[],"timeline":[{"date":"2022-03-28","kind":"published","label":"Published (CVE.org)","url":"https://www.cve.org/CVERecord?id=CVE-2022-0342","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":null},"priority":{"score":67.5,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 377 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.97,"detail":"percentile 0.9986"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 nuclei template"},{"name":"Mentioned in OTX pulses","points":0.68,"detail":"1 pulse"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}