CVE-2020-29583

Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an...

9.8 CriticalIn KEVPublic exploit

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

90.2%Up 83.6 points since Apr 14, 2021

What each source reports

NVD Score used 9.8

Record: CVE-2020-29583
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 10.0 HighAV:N/AC:L/Au:N/C:C/I:C/A:C
Weakness: CWE-522
Updated: 2026-11-02

CVE List 9.8

Record: CVE-2020-29583
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-522
Updated: 2026-11-02

EUVDEUVD-2020-21944 9.8

Record: EUVD-2020-21944
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-59jx-m3c4-2m9w 9.8

Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an...

Record: GHSA-59jx-m3c4-2m9w
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-312, CWE-522
Updated: 2026-11-02

CISA KEV No score

Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability

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.

Record: CVE-2020-29583
Weakness: CWE-522
Updated: 2026-11-02

Affected products

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Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	ruppde/scan_CVE-2020-29583	2021-01-04
Nuclei	ZyXel USG - Hardcoded Credentials

History

History
Recorded	Changed	Sources
Nov 3, 2026	exploitation, exploits
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, CISA KEV, Nuclei, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-29583 is a critical vulnerability (CVSS 9.8) in Zyxel Atp100 Firmware, published December 22, 2020. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 90.2%, the 99th percentile. No source names a fixed version.

References

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