Hazard

Is CVE-2020-29583 being exploited?

Weaponised and widely attempted

Reliable public exploit code exists, or mass exploitation attempts are probable. Patch inside days, not weeks.

Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability

Zyxel · Multiple Products

CVSS 9.8 EPSS 90% no public exploit indexed Fix deadline passed 3 May 2022

What it is

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.

Why we say that

  • EPSS puts exploitation in the next 30 days at 90%
  • CISA's federal remediation deadline (2022-05-03) has passed
  • CVSS 9.8 critical
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

Apply updates per vendor instructions.

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:

All UK cases caused by unpatched software →