CVE-2020-29583
Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability
Does this matter?
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.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 90.16% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 3 November 2021 · due 3 May 2022
- Weakness
- 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 · +10 more
- Source
- cve@mitre.org
EPSS 90.2% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2020-29583
References
- http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdfBroken Link
- https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-releaseRelease Notes
- https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15Release Notes
- https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.htmlBroken Link, Third Party Advisory
- https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/Exploit, Third Party Advisory
- https://www.zyxel.com/support/CVE-2020-29583.shtmlVendor Advisory
- https://www.zyxel.com/support/security_advisories.shtmlVendor Advisory
- http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdfBroken Link
- https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-releaseRelease Notes
- https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15Release Notes
- https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.htmlBroken Link, Third Party Advisory
- https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/Exploit, Third Party Advisory
- https://www.zyxel.com/support/CVE-2020-29583.shtmlVendor Advisory
- https://www.zyxel.com/support/security_advisories.shtmlVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-29583US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.