Vulnerability in Python Software Foundation Cpython

CVE-2024-5642

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).

EPSS: 0.007 (51.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.

Affected products

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-5642?
CVE-2024-5642 is a medium-severity vulnerability in Python Software Foundation Cpython. CVSS score: 6.5/10. Published 2024-06-27.
How severe is CVE-2024-5642?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2024-5642 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.