CVE-2023-0465: Invalid certificate policies in leaf certificates are silently ignored

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-03-28 · updated 2026-10-14
Weakness: CWE-295

Description

Applications that use a non-default option when verifying certificates may be vulnerable to an attack from a malicious CA to circumvent certain checks. Invalid certificate policies in leaf certificates are silently ignored by OpenSSL and other certificate policy checks are skipped for that certificate. A malicious CA could use this to deliberately assert invalid certificate policies in order to circumvent policy checking on the certificate altogether. Policy processing is disabled by default but can be enabled by passing the `-policy' argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()' function.

Affected products

OpenSSL: from 1.0.2 before 1.0.2zh; from 1.1.1 before 1.1.1u; from 3.0.0 before 3.0.9; from 3.1.0 before 3.1.1 — fixed in 1.0.2zh, 1.1.1u, 3.0.9, 3.1.1

How to fix

Upgrade to a fixed version: OpenSSL 1.0.2zh, 1.1.1u, 3.0.9, 3.1.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2023-0465 or the next vulnerability affects your stack