What is CVE-2023-27152?

CVE-2023-27152 is a critical-severity vulnerability in Opnsense, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2023-10-23.

How severe is CVE-2023-27152?

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

Is CVE-2023-27152 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Opnsense

CVE-2023-27152

DECISO OPNsense 23.1 does not impose rate limits for authentication, allowing attackers to perform a brute-force attack to bypass authentication.

Published 2023-10-23 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.009 (57.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Opnsense — versions 23.1

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

Public proof-of-concept exploits

References

www.esecforte.com/cve-2023-27152-opnsense-brute-force/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2023-27152?: CVE-2023-27152 is a critical-severity vulnerability in Opnsense, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2023-10-23.
How severe is CVE-2023-27152?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2023-27152 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.