CVE-2020-29583
Confirmed PUBLISHEDFirmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. The password for this account...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Dec 22, 2020
- Exploitation Reported
- Nov 03, 2021
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- zyxel.com/support/security_advisories.shtml zyxel.com · CVE Record https://www.zyxel.com/support/security_advisories.shtml
- ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf ftp.zyxel.com · CVE Record http://ftp.zyxel.com/USG40/firmware/USG40_4.60%28AALA.1%29C0_2.pdf
- businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-... businessforum.zyxel.com · CVE Record https://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60...
- businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-fi... businessforum.zyxel.com · CVE Record https://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-...
- eyecontrol.nl/blog/undocumented-user-account-in-zyxel-prod... eyecontrol.nl · CVE Record https://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-pro...
Show 2 more references
- zyxel.com/support/CVE-2020-29583.shtml zyxel.com · CVE Record https://www.zyxel.com/support/CVE-2020-29583.shtml
- secpod.com/blog/a-secret-zyxel-firewall-and-ap-controll... secpod.com · CVE Record https://www.secpod.com/blog/a-secret-zyxel-firewall-and-ap-controller...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-29583.yaml | Apr 25, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:L/Au:N/C:C/I:C/A:C
Exploitation Status
Exploited in the wild
Recorded 2021-11-03 00:00:00 UTC · CISA
Proof of concept available
Recorded 2021-01-04 00:56:55 UTC · GitHub
Weaknesses (CWE)
-
Insufficiently Protected Credentials
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-29583.yaml | Apr 25, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2021-01-04 00:56:55 UTC · 15 stars
Scanner for Zyxel products which are potentially vulnerable due to an undocumented user account (CVE-2020-29583)
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC about 1 year ago00:00 UTC · about 1 year ago
Nuclei template available
Scanner coverage available
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
00:56 UTC over 5 years ago00:56 UTC · over 5 years ago
Public PoC available
Public proof-of-concept code published
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2020-29583
{
"cve_id": "CVE-2020-29583",
"title": "Firmware version 4.60 of Zyxel USG devices contains an undocumented account (...",
"affected_vendor": "Zyxel",
"affected_product": "USG devices",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}