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 an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.

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

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . 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: .

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

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.