Vulnerability Report

CVE-2020-29583

CISA KEV Active

Title: Undocumented account in Zyxel USG devices

vb

Proof Of Concept

No public PoC currently indexed for CVE-2020-29583.

CWE Category CWE-522
Published Date Dec 22, 2020
Modified Date Nov 07, 2025
Exploit Status Not Found
Score 9.8 CVSS v3.1
Exploit Probability (EPSS)
90.15%

Vulnerability Summary

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 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.

Impacted Vendors

Z
zyxel 30
H
huawei 1

Reference Links

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
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity HIGH
10.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:N/C:C/I:C/A:C

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2020-29583 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.