CVE-2023-27992 kev in the critical feed json
The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware ver…
published 2023-06-19 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-31717
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Exploited
- added 2023-06-23
- epss
- 82.3%
- EPSS 82.3% chance of exploitation in 30 days, percentile 99.6%
- public exploits
- 0
- none known
Summary
The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.
Patch / fix
cisa required action Apply updates per vendor instructions.
- zyxel nas326_firmware 5.21\(aazf.14\)c0
- zyxel nas540_firmware 5.21\(aatb.11\)c0
- zyxel nas542_firmware 5.21\(abag.11\)c0
Timeline
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 3 y ago
- Patch by
- 2023-07-14 (3 y ago)
- Ransomware
- Not known
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- Zyxel, Multiple Network-Attached Storage (NAS) Devices
- CISA name
- Zyxel Multiple NAS Devices Command Injection Vulnerability
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- yes
- Technical impact
- total
- Assessed
- 21 mo ago
Exploit prediction
82.26% chance of exploitation in the next 30 days, higher than 99.6% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Zyxel NAS326 firmware
- Zyxel NAS540 firmware
- Zyxel NAS542 firmware
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
-
zyxel.com
/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulner
patch, vendor-advisory
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27992
government-resource, us-government-resource
Sources
- CVE List CVE-2023-27992
- NVD CVE-2023-27992
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