CVE-2024-5642
Buffer overread when using an empty list with SSLContext.set_npn_protocols()
At a glance
- Severity
- MEDIUM 6.5
- EPSS
- EPSS 0.74 % · percentile 55 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- PSF
- NVD status
- Deferred
Description
CPython 3.9 and earlier doesn't disallow configuring an empty list ("[]") for SSLContext.set_npn_protocols() which is an invalid value for the underlying OpenSSL API. This results in a buffer over-read when NPN is used (see CVE-2024-5535 for OpenSSL). This vulnerability is of low severity due to NPN being not widely used and specifying an empty list likely being uncommon in-practice (typically a protocol name would be configured).
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L | CISA-ADP |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2024-46822
- GCVE · GCVE-0-2024-5642
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0556 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0281 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0218 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0199 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0969 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0967 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0864 — Multiples vulnérabilités dans VMware Tanzu · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0661 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
- CERTFR-2024-AVI-0540 — Multiples vulnérabilités dans Python · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Python Software Foundation · CPython | affected 0 < 3.9.24 ; affected 3.10.0a1 < 3.10.0b1 |
References
- https://jbp.io/2024/06/27/cve-2024-5535-openssl-memory-safety.html
- https://github.com/python/cpython/pull/23014
- https://mail.python.org/archives/list/security-announce@python.org/thread/PLP2JI3PJY33YG6P5BZYSSNU66HASXBQ/
- https://github.com/python/cpython/commit/39258d3595300bc7b952854c915f63ae2d4b9c3e
- http://www.openwall.com/lists/oss-security/2024/06/28/4
- https://github.com/python/cpython/issues/121227
- https://security.netapp.com/advisory/ntap-20240726-0005/
- https://github.com/python/cpython/commit/a2cdbb6e8188ba9ba8b356b28d91bff60e86fe31
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |