CVE-2020-29583
Critical CVSS 9.8 Known exploitedPublished 2020-12-22 · last changed 2026-06-17 · added to CISA KEV 2021-11-03
The fix
We hold no Microsoft remediation data for CVE-2020-29583, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.
What it is
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.
Sources
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H