CVE-2024-0397 — A defect was discovered in the Python “ssl” module where there is a memory race

A defect was discovered in the Python “ssl” module where there is a memory race condition with the ssl.SSLContext methods “cert_store_stats()” and “get_ca_certs()”. The race condition can be triggered if the methods are called at the same time as certificates are loaded into the

01What is this vulnerability?

A defect was discovered in the Python “ssl” module where there is a memory race condition with the ssl.SSLContext methods “cert_store_stats()” and “get_ca_certs()”. The race condition can be triggered if the methods are called at the same time as certificates are loaded into the SSLContext, such as during the TLS handshake with a certificate directory configured. This issue is fixed in CPython…

02Affected products

Vendor	Product	Versions
Python Software Foundation	CPython	0, 3.9.0, 3.10.0, 3.11.0, 3.12.0, 3.13.0a1

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

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

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: 2024-06-17T15:09:40.896Z
• Last modified: 2025-11-03T21:50:55.091Z

09References

• github.com — https://github.com/python/cpython/issues/114572
• github.com — https://github.com/python/cpython/pull/114573
• mail.python.org — https://mail.python.org/archives/list/[email protected]/thread/BMAK5B…
• github.com — https://github.com/python/cpython/commit/01c37f1d0714f5822d34063ca7180b595abf589…
• github.com — https://github.com/python/cpython/commit/29c97287d205bf2f410f4895ebce3f43b516052…
• github.com — https://github.com/python/cpython/commit/37324b421b72b7bc9934e27aba85d48d4773002…
• github.com — https://github.com/python/cpython/commit/542f3272f56f31ed04e74c40635a913fbc12d28…
• github.com — https://github.com/python/cpython/commit/b228655c227b2ca298a8ffac44d14ce3d22f6fa…
• github.com — https://github.com/python/cpython/commit/bce693111bff906ccf9281c22371331aaff766a…
• www.openwall.com — http://www.openwall.com/lists/oss-security/2024/06/17/2