What is CVE-2023-39004?

CVE-2023-39004 is a critical-severity vulnerability in Opnsense, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 9.8/10. Published 2023-08-09.

How severe is CVE-2023-39004?

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

Is CVE-2023-39004 known to be exploited?

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

Vulnerability in Opnsense

CVE-2023-39004

Insecure permissions in the configuration directory (/conf/) of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allow attackers to access sensitive information (e.g., hashed root password) which could lead to privilege escalation.

Published 2023-08-09 · last modified 2026-07-09.

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: 0.010 (60.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 60.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: +0.000

Affected products

Opnsense

Weakness classification (CWE)

CWE-732 — Incorrect Permission Assignment for Critical Resource

Public proof-of-concept exploits

References

af854a3a-2127-422b-91ae-364da2661108 (Product)
logicaltrust.net/blog/2023/08/opnsense.html (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2023-39004?: CVE-2023-39004 is a critical-severity vulnerability in Opnsense, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 9.8/10. Published 2023-08-09.
How severe is CVE-2023-39004?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2023-39004 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.