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Public proof of conceptFix available

CVE-2023-0464

A public proof of concept exists; no exploitation attested.

  • Published2023-03-22
  • Fixed in3.1.1 · 3.0.9 · 1.1.1u · 1.0.2zh
  • WeaknessCWE-295

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2023-03-2217:15CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-0464?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-0464?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
OpenSSL
BranchAffectedFixed in
3.1≥ 3.1.0, < 3.1.13.1.1
3.0≥ 3.0.0, < 3.0.93.0.9
1.1≥ 1.1.1, < 1.1.1u1.1.1u
1.0≥ 1.0.2, < 1.0.2zh1.0.2zh

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • opensslAlmaLinux:9all versions · fixed in 1:3.0.7-16.el9_2and 3 other packages

Vendor advisories

  • ICSA-25-226-21 CISA1 known affected

    Siemens BFCClient

    BFCClient

  • ICSA-24-165-11 CISA26 known affected

    Siemens SCALANCE XM-400, XR-500

    SCALANCE XM408-4C (6GK5408-4GP00-2AM2) · SCALANCE XM408-4C (L3 int.) (6GK5408-4GQ00-2AM2) · SCALANCE XM408-8C (6GK5408-8GS00-2AM2) · +23 more

Full record on NVD

Fix

  1. Update OpenSSL to 3.1.1 · 3.0.9 · 1.1.1u · 1.0.2zh
  2. Vendor fix CISA ICSA-25-226-21 · 1 productUpdate to V2.17 or later version. Contact customer support to obtain the update
  3. Vendor fix CISA ICSA-24-165-11 · 26 productsUpdate to V6.6.1 or later version

Advisories and patches

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedTrinadh465/Openssl_1.1.1g_CVE-2023-0464
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2023-03-22
Last Modified
2026-10-14
NVD status
Modified

Frequently asked questions

What is CVE-2023-0464?

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.

Is CVE-2023-0464 actively exploited?

Active exploitation of CVE-2023-0464 has not been confirmed. Its EPSS score was 4.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-0464?

CVE-2023-0464 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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