What is the CVSS score of CVE-2020-29583?

CVE-2020-29583 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 90.0%.

Is there a public PoC exploit available for CVE-2020-29583?

Yes, a public proof-of-concept exploit is available for CVE-2020-29583. Prioritise patching immediately. EPSS: 90.0%.

Usg20 Vpn Firmware CVE-2020-29583

CRITICAL

Insufficiently Protected Credentials (CWE-522)

2020-12-22 cve@mitre.org

Zyxel Information Disclosure Usg20 Vpn Firmware Usg20W Vpn Firmware Usg40 Firmware Usg40W Firmware Usg60 Firmware Usg60W Firmware Usg110 Firmware Usg210 Firmware Usg310 Firmware Usg1100 Firmware Usg1900 Firmware Usg2200 Firmware Zywall110 Firmware Zywall310 Firmware Zywall1100 Firmware Atp100 Firmware Atp100W Firmware Atp200 Firmware Atp500 Firmware Atp700 Firmware Atp800 Firmware Vpn50 Firmware Vpn100 Firmware Vpn300 Firmware Vpn1000 Firmware Usg Flex 100 Firmware Usg Flex 100W Firmware Usg Flex 200 Firmware Usg Flex 500 Firmware Usg Flex 700 Firmware

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Added to CISA KEV

Jul 14, 2026 - 04:22 CISA

CVE Published

Dec 22, 2020 - 22:15 nvd

CRITICAL 9.8

DescriptionNVD

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.

AnalysisAI

Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Insufficiently Protected Credentials (CWE-522), which allows attackers to obtain user credentials due to weak protection mechanisms. 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. Affected products include: Zyxel Usg20-Vpn Firmware, Zyxel Usg20W-Vpn Firmware, Zyxel Usg40 Firmware, Zyxel Usg40W Firmware, Zyxel Usg60 Firmware. Version information: version 4.60.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Hash passwords with strong algorithms (bcrypt, argon2), encrypt credentials in transit and at rest, never log credentials.