CVE-2023-0464

Excessive Resource Usage Verifying X.509 Policy Constraints

HIGH
7.5
CVSS Score
Published: March 22, 2023 at 04:36 PM UTC
Updated: October 14, 2026 at 08:17 PM UTC
1 product affected across 1 vendorOpenSSL

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Severity
HIGH7.5
Exploit prediction
EPSS 4%
SSVC
No known exploit

Description

A security vulnerability has been identified in all supported versions of OpenSSL related to the verification of X.509 certificate chains that include policy constraints. Attackers may be able to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial-of-service (DoS) attack on affected systems. 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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.0.2 ≤ v < 1.0.2zh1.1.1 ≤ v < 1.1.1u3.0.0 ≤ v < 3.0.93.1.0 ≤ v < 3.1.11.0.21.1.13.0.03.1.0
Affected range stops below 1.0.2zh, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.1.1u, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.0.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.1.1, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-295

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