CVE-2020-29583
· published 2020-12-22
Source record Collected from the National Vulnerability Database (NVD)
CISA Known Exploited Vulnerabilities
CISA lists this CVE as known exploited (added 2021-11-03).
- CISA's name for it: Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability
- CISA's description: Zyxel firewalls (ATP, USG, VM) and AP Controllers (NXC2500 and NXC5500) contain a use of hard-coded credentials vulnerability in an undocumented account ("zyfwp") with an unchangeable password.
- Known ransomware campaign use, per CISA: Unknown
Source: CISA KEV catalog (CC0 1.0).
Description
Description by MITRE via the CVE Program.
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.
Status at the source
- NVD status: Analyzed
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| n/a | n/a | n/a: affected |
Products named in NVD's CPE match criteria (30)
cpe:2.3:o:zyxel:usg20-vpn_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg20w-vpn_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg40_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg40w_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg60_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg60w_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg110_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg210_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg310_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg1100_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg1900_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg2200_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:zywall110_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:zywall310_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:zywall1100_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp100_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp100w_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp200_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp500_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp700_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:atp800_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:vpn50_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:vpn100_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:vpn300_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:vpn1000_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg_flex_100_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg_flex_100w_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg_flex_200_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg_flex_500_firmware:4.60:*:*:*:*:*:*:*cpe:2.3:o:zyxel:usg_flex_700_firmware:4.60:*:*:*:*:*:*:*
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 3.1: 9.8 CRITICAL — as published by NIST (Primary)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1: 9.8 CRITICAL — as published by CISA-ADP (Secondary)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0: 10 HIGH — as published by NIST (Primary)
AV:N/AC:L/Au:N/C:C/I:C/A:C - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: active · Automatable: yes · Technical impact: total
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
- 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/
- https://www.zyxel.com/support/CVE-2020-29583.shtml
- 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/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/
- https://www.zyxel.com/support/CVE-2020-29583.shtml
- https://www.zyxel.com/support/security_advisories.shtml
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-29583
Source dates: published 2020-12-22, last changed 2026-06-17. DeSpy's copy of this version is dated 2026-09-28.
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