Back
CVE-2023-27992
The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware…
Critical9.8Known exploitedEPSS 82.3%
- Published
- Updated
- Reserved
- Assigned by
- Zyxel
Description
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Zyxel Multiple NAS Devices Command Injection Vulnerability.
- Added
- 23 Jun 2023
- Fix due (US federal)
- 14 Jul 2023
- Used by ransomware
- Not known
Apply updates per vendor instructions.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ZyxelCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 82.3% · top 0.3% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
- affected < V5.21(AAZF.14)C0
- affected < V5.21(AATB.11)C0
- affected < V5.21(ABAG.11)C0
References (2)
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products (opens in a new tab)x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27992 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-27992)Record last updated .