Threats / Zyxel / CVE-2020-9054
CVE-2020-9054
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Zyxel Multiple Network-Attached Storage (NAS) Devices vulnerability
Multiple Zyxel NAS devices are vulnerable to pre-authentication command injection (CWE-78), allowing remote unauthenticated attackers to execute arbitrary code. The vulnerability has been exploited in the wild.
Verdict
Today item — known-exploited.
A critical pre-authentication remote code execution flaw in Zyxel NAS appliances enables attackers to gain immediate system-level access without credentials. Active exploitation in the wild and high EPSS score indicate urgent remediation priority.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
596 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25).
Probability (EPSS)
EPSS 0.99988 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Zyxel, Multiple Network-Attached Storage (NAS) Devices. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious command injection payload targeting the unauthenticated interface of a Zyxel NAS device.
Business
Attackers bypass all authentication controls and gain direct code execution capability on network storage infrastructure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary system commands with the privileges of the NAS service process.
Business
Stored data, backups, and connected network resources become accessible to the attacker without detection by normal access controls.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistent access or deploy additional malware to maintain control across reboots.
Business
The compromised NAS becomes a persistent foothold for lateral movement, data exfiltration, or further network compromise.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05