What is CVE-2023-27992?

CVE-2023-27992 is a critical-severity vulnerability in Zyxel Nas326, classified under OS Command Injection. CVSS score: 9.8/10. Published 2023-06-19.

How severe is CVE-2023-27992?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2023-27992 known to be exploited?

Yes. CVE-2023-27992 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-06-23), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

RCE in Zyxel Nas326

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 prior to V5.21(ABAG.11)C0 could allow…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.842 (99.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Zyxel Nas326
Zyxel Nas326 Firmware — versions < V5.21(AAZF.14)C0
Zyxel Nas326_firmware
Zyxel Nas540
Zyxel Nas540 Firmware — versions < V5.21(AATB.11)C0
Zyxel Nas540_firmware
Zyxel Nas542
Zyxel Nas542 Firmware — versions < V5.21(ABAG.11)C0
Zyxel Nas542_firmware

Weakness classification (CWE)

CWE-78 — OS Command Injection

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2023-06-23. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2023-07-14.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

security@zyxel.com.tw (Patch, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2023-27992?: CVE-2023-27992 is a critical-severity vulnerability in Zyxel Nas326, classified under OS Command Injection. CVSS score: 9.8/10. Published 2023-06-19.
How severe is CVE-2023-27992?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2023-27992 known to be exploited?: Yes. CVE-2023-27992 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-06-23), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.