CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2020-29583
Critical (9.8) in Zyxel Multiple Products. In CISA KEV since 2021-11-03. EPSS 90% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 90% chance of exploitation in the next 30 days; higher than 99% of CVEs (scores of 2026-10-31)
- CISA KEV
- listed 2021-11-03, due 2022-05-03
- CWE
- CWE-522
- Published
- Modified
- Record from
- the NVD, synced
Affected
- zyxel:atp100_firmware
- zyxel:atp100w_firmware
- zyxel:atp200_firmware
- zyxel:atp500_firmware
- zyxel:atp700_firmware
- zyxel:atp800_firmware
- zyxel:usg1100_firmware
- zyxel:usg110_firmware
- zyxel:usg1900_firmware
- zyxel:usg20-vpn_firmware
- zyxel:usg20w-vpn_firmware
- zyxel:usg210_firmware
- zyxel:usg2200_firmware
- zyxel:usg310_firmware
- zyxel:usg40_firmware
- zyxel:usg40w_firmware
- zyxel:usg60_firmware
- zyxel:usg60w_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
- zyxel:vpn1000_firmware
- zyxel:vpn100_firmware
- zyxel:vpn300_firmware
- zyxel:vpn50_firmware
- zyxel:zywall1100_firmware
- zyxel:zywall110_firmware
- zyxel:zywall310_firmware
References
- http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf
- https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-release
- https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15
- https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.html
- https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controllers-could-allow-for-administrative-access-cve-2020-29583/