CVE-2020-29583
CyberVault Technical Summary
Analyst SynthesisTechnical analysis, exploit verification, and patch instructions for CVE-2020-29583 impacting zyxel usg20-vpn_firmware. Evaluated with CVSS Base Score of 9.8 (CRITICAL).
Original NVD Description
Source: NIST NVD📊 CVSS v3.1 Metric Breakdown
🎯 Affected Versions Matrix
| Affected Product | zyxel / usg20-vpn_firmware |
| Affected Versions | 4.60 |
| Weakness Enumeration | CWE-522 |
Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe
Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2020-29583 impacting zyxel usg20-vpn_firmware.
id: cve-2020-29583
info:
name: zyxel usg20-vpn_firmware - Security Advisory & Vulnerability Scan
author: cybervault-security-intel
severity: critical
description: |
Automated signature & scanner for CVE-2020-29583 affecting zyxel usg20-vpn_firmware.
Evaluation: Firmware version 4.60 of Zyxel USG devices contains an undocumented account (zyfwp) with an unchangeable password. The password for this account can b...
reference:
- https://cybervault-cve.pages.dev/cve/CVE-2020-29583
classification:
cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cvss-score: 9.8
cve-id: CVE-2020-29583
cwe-id: CWE-522
tags: cve,cve-2020-29583,zyxel,usg20-vpn_firmware,critical
http:
- method: GET
path:
- "{BaseURL}/"
- "{BaseURL}/api/"
matchers-condition: and
matchers:
- type: status
status:
- 200
- type: word
words:
- "usg20-vpn_firmware"
part: body
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-29583
# Target: zyxel usg20-vpn_firmware | CVSS: 9.8 (CRITICAL)
# Educational & Security Audit Purpose Only
import requests
import sys
def verify_vulnerability(target_url):
print(f"[*] Auditing {target_url} for CVE-2020-29583 (zyxel usg20-vpn_firmware)...")
headers = {
"User-Agent": "CyberVault-Audit-Scanner/2.0",
"Accept": "*/*"
}
try:
r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
if r.status_code < 500:
print(f"[!] Target reachable. Verify version against zyxel usg20-vpn_firmware scope (4.60).")
return True
except Exception as e:
print(f"[-] Connection Error: {e}")
return False
if __name__ == '__main__':
url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
verify_vulnerability(url)
# Recommended Remediation & Patching Commands for CVE-2020-29583
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install usg20-vpn_firmware 2>/dev/null || \
sudo dnf upgrade usg20-vpn_firmware 2>/dev/null || \
sudo yum update usg20-vpn_firmware
# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i usg20-vpn_firmware 2>/dev/null || rpm -qa | grep -i usg20-vpn_firmware
# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."
🛡️ Remediation & Security Action
- Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
- Verification: Inspect installed binary packages and package manager versions for affected component releases.
- Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
🔗 Verified Technical References
- No records filed in this category.
- ↗ 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/
❓ Frequently Asked Questions (FAQ) & Remediation Guide
How do I fix CVE-2020-29583 in zyxel usg20-vpn_firmware?
Review vendor-specific security notices and update zyxel usg20-vpn_firmware packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.
Is there an active exploit or public PoC for CVE-2020-29583?
No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.
What is the CVSS 3.1 severity rating and impact for CVE-2020-29583?
CVE-2020-29583 is classified with a CVSS 3.1 Base Score of 9.8 (CRITICAL). Check the metric breakdown above for attack vector requirements.