OpenSSLFramework / library
CVE-2023-0464
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe application does not properly validate the TLS certificate presented by the other side — skipping the chain, the hostname, or expiry — so an attacker with a forged or mismatched certificate can sit in the middle of a supposedly secure connection. It is a common trap in custom clients and misconfigured libraries. The fix is full certificate validation, and never disabling verification to make errors go away.
General guidance for the improper certificate validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
OpenSSLFramework / library
>= 1.0.2, < 1.0.2zh>= 1.1.1, < 1.1.1u>= 3.0.0, < 3.0.9>= 3.1.0, < 3.1.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.0.2zh1.1.1u3.0.9
OpenSSL 1.0.2zh, 1.1.1u, 3.0.9, or 3.1.1 (depending on current branch)
- 1. Identify the current OpenSSL version installed by running: openssl version -a
- 2. Determine which affected version branch your installation belongs to (1.0.2, 1.1.1, 3.0.x, or 3.1.x)
- 3. For OpenSSL 1.0.2: Upgrade to version 1.0.2zh or later
- 4. For OpenSSL 1.1.1: Upgrade to version 1.1.1u or later
- 5. For OpenSSL 3.0.x: Upgrade to version 3.0.9 or later
- 6. For OpenSSL 3.1.x: Upgrade to version 3.1.1 or later
- 7. After upgrading, verify the new version with: openssl version -a
- 8. Test certificate chain validation functionality to ensure normal operation
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-0464 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-0464 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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