CVE-2023-35784 — A double free or use after free could occur after SSL_clear in OpenBSD 7
A double free or use after free could occur after SSL_clear in OpenBSD 7.2 before errata 026 and 7.3 before errata 004, and in LibreSSL before 3.6.3 and 3.7.x before 3.7.3. NOTE: OpenSSL is not affected.
Published
2023-06-16T00:00:00.000Z
Last modified
2024-12-17T17:05:30.289Z
01What is this vulnerability?
A double free or use after free could occur after SSL_clear in OpenBSD 7.2 before errata 026 and 7.3 before errata 004, and in LibreSSL before 3.6.3 and 3.7.x before 3.7.3. NOTE: OpenSSL is not affected.
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:
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07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2023-06-16T00:00:00.000Z
- Last modified: 2024-12-17T17:05:30.289Z
09References
- ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/patches/7.3/common/004_ssl.patch.sig
- ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/patches/7.2/common/026_ssl.patch.sig
- ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-3.6.3-relnotes.txt
- ftp.openbsd.org — https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-3.7.3-relnotes.txt
- github.com — https://github.com/libressl/openbsd/commit/e42d8f4b21a8a498e2eabbffe4c7b7d4ef7ce…
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