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CVE-2020-29583

Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. The password for this account...

Basic Information

CVE State
PUBLISHED
Reserved Date
December 06, 2020
Published Date
December 22, 2020
Last Updated
October 21, 2025
Vendor
Zyxel
Product
USG devices
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.
Tags
cisa nuclei_scanner edge

CVSS Scores

CVSS v3.1

9.8 - CRITICAL

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v2.0

10.0

Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C

SSVC Information

Exploitation
active
Automatable
Yes
Technical Impact
total

Exploit Status

Exploited in the Wild
Yes (2021-11-03 00:00:00 UTC) Source

References

https://www.zyxel.com/support/security_advisories.shtml http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15 https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-release https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.html https://www.zyxel.com/support/CVE-2020-29583.shtml https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/

Known Exploited Vulnerability Information

Source Added Date
CISA 2021-11-03 00:00:00 UTC
CISA 2021-11-03 00:00:00 UTC

Scanner Integrations

Scanner URL Date Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-29583.yaml 2025-04-25 00:00:00 UTC

Potential Proof of Concepts

Warning: These PoCs have not been tested and could contain malware. Use at your own risk.

ruppde/scan_CVE-2020-29583

Type: github • Created: 2021-01-04 00:56:55 UTC • Stars: 15

Scanner for Zyxel products which are potentially vulnerable due to an undocumented user account (CVE-2020-29583)

Timeline

  • CVE ID Reserved

  • CVE Published to Public

  • Added to KEVIntel

  • Added to KEVIntel

  • Detected by Nuclei