01 Record
CVE-2023-27992
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
CriticalKEVPUBLISHEDCNA: Zyxel
CNA base score9.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
02 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
03 Exploitation and scoring
- Exploitation
- Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2023-06-23. Federal remediation due 2023-07-14.
- SSVC decision
- ExploitationactiveCISA reports credible evidence of active exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 82.26% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.6% of scored records. A rank, not a probability.
- NVD base score
- 9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2023-06-19 11:42Z3 YR AGO
- Last updated
- 2025-10-21 23:05Z1 YR AGO
- Reserved
- 2023-03-09
- Assigning CNA
- Zyxel
- Record state
- PUBLISHED
- Severity
- Critical (CVSS 9.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')Base
- Data version
- 5.1
- Document digest
- 978b483c65debe74afedd9539d4e6be9a7b87ee897da89378fd9e606bf4fbbfe
05 Affected products
VendorProductVersionsPlatforms