CVE-2024-5642

Buffer overread when using an empty list with SSLContext.set_npn_protocols()

Published Jun 27, 2024 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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).

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2024-46822 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).
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 2.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
PSF
Published
Updated
Jul 31, 2026, 2:06 PM
Reserved
Jun 4, 2024, 6:40 PM
Status
Deferred
Published
Jun 27, 2024, 9:15 PM
Modified
Jul 31, 2026, 3:16 PM
Severity
Low
Public date
Jun 27, 2024, 12:00 AM