{"id":"CVE-2020-29583","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-29583","generatedAt":"2026-10-31T16:13:54.308Z","title":"Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability","description":"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 account can be used by someone to login to the ssh server or web interface with admin privileges.","published":"2020-12-22T22:15:14.000Z","lastModified":"2026-06-17T03:11:29.000Z","status":"Analyzed","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-522"],"affected":["zyxel/usg20-vpn firmware","zyxel/usg20w-vpn firmware","zyxel/usg40 firmware","zyxel/usg40w firmware","zyxel/usg60 firmware","zyxel/usg60w firmware","zyxel/usg110 firmware","zyxel/usg210 firmware","zyxel/usg310 firmware","zyxel/usg1100 firmware","zyxel/usg1900 firmware","zyxel/usg2200 firmware","zyxel/zywall110 firmware","zyxel/zywall310 firmware","zyxel/zywall1100 firmware","zyxel/atp100 firmware","zyxel/atp100w firmware","zyxel/atp200 firmware","zyxel/atp500 firmware","zyxel/atp700 firmware","zyxel/atp800 firmware","zyxel/vpn50 firmware","zyxel/vpn100 firmware","zyxel/vpn300 firmware","zyxel/vpn1000 firmware","zyxel/usg flex 100 firmware","zyxel/usg flex 100w firmware","zyxel/usg flex 200 firmware","zyxel/usg flex 500 firmware","zyxel/usg flex 700 firmware"],"epss":{"score":0.90155,"percentile":0.99796,"date":"2026-10-30","history":[]},"kev":{"listed":true,"dateAdded":"2021-11-03","dueDate":"2022-05-03","knownRansomwareCampaignUse":"Unknown","notes":"Apply updates per vendor instructions.\nhttps://nvd.nist.gov/vuln/detail/CVE-2020-29583"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf","tags":["Broken Link"],"source":"cve@mitre.org"},{"url":"https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-release","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.html","tags":["Broken Link","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.zyxel.com/support/CVE-2020-29583.shtml","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.zyxel.com/support/security_advisories.shtml","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf","tags":["Broken Link"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-release","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.html","tags":["Broken Link","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.zyxel.com/support/CVE-2020-29583.shtml","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.zyxel.com/support/security_advisories.shtml","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-29583","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-29583","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}