OpenSSL: Improper Certificate Validation
CVE-2023-0464 is a high-severity improper certificate validation vulnerability in OpenSSL, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 3.1.1, 3.0.9, 1.1.1u as the first without the flaw, so updating OpenSSL to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.98% chance of exploitation within 30 days, which is in the top 9.33% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update OpenSSL to 3.1.1 or 3.0.9 or 1.1.1u or 1.0.2zh, whichever matches your release line, or a later version.
- Update BFCClient to V2.17 or a later version.
- Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
- Read the advisory on openssl.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| OpenSSL | OpenSSL | 3.1.0 up to, but not including, 3.1.1; 3.0.0 up to, but not including, 3.0.9; 1.1.1 up to, but not including, 1.1.1u; 1.0.2 up to, but not including, 1.0.2zh | 3.1.1, 3.0.9, 1.1.1u, 1.0.2zh |
| Siemens | BFCClient | before V2.17 | V2.17 |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | before V1.1 | V1.1 |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2017771e2db3e2b96f89bbe8766c3209f6a99545Mailing List
- git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=879f7080d7e141f415c79eaa3a8ac4a3dad0348bMailing List
- git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=959c59c7a0164117e7f8366466a32bb1f8d77ff1Mailing List
Other references
- lists.debian.org/debian-lts-announce/2023/06/msg00011.html
- security.gentoo.org/glsa/202402-08
- security.netapp.com/advisory/ntap-20240621-0006/
- couchbase.com/alerts/
- debian.org/security/2023/dsa-5417
- security.netapp.com/advisory/ntap-20230406-0006/
- cert-portal.siemens.com/productcert/html/ssa-028723.html
- cert-portal.siemens.com/productcert/html/ssa-077170.html
- cert-portal.siemens.com/productcert/html/ssa-337522.html
- cert-portal.siemens.com/productcert/html/ssa-341067.html
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- cert-portal.siemens.com/productcert/html/ssa-556635.html
- cert-portal.siemens.com/productcert/html/ssa-625862.html
- cert-portal.siemens.com/productcert/html/ssa-769027.html
- cert-portal.siemens.com/productcert/html/ssa-794697.html
Other vulnerabilities in OpenSSL
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
Recent Improper Certificate Validation vulnerabilities
- 8.1 High severity
- 7.4 High severity
- 7.4 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 8.3 High severity
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