CVE-2024-5642
Buffer overread when using an empty list with SSLContext.set_npn_protocols()
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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).
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://github.com/python/cpython/commit/39258d3595300bc7b952854c915f63ae2d4b9c3e
- https://github.com/python/cpython/pull/23014
- https://mail.python.org/archives/list/[email protected]/thread/PLP2JI3PJY33YG6P5BZYSSNU66HASXBQ/
- https://github.com/python/cpython/commit/a2cdbb6e8188ba9ba8b356b28d91bff60e86fe31
References (8)
SSVC — Action Prioritization
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- LOW
- Integrity
- NONE
- Availability
- LOW
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