// For flags

CVE-2024-5642

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

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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).

CPython 3.9 y versiones anteriores no permiten la configuración de una lista vacía ("[]") para SSLContext.set_npn_protocols(), que es un valor no válido para la API OpenSSL subyacente. Esto da como resultado una lectura excesiva del búfer cuando se utiliza NPN (consulte CVE-2024-5535 para OpenSSL). Esta vulnerabilidad es de baja gravedad debido a que NPN no se usa ampliamente y especificar una lista vacía probablemente sea poco común en la práctica (normalmente se configuraría un nombre de protocolo).

This update for python39 fixes the following issues. Fixed email header injection due to unquoted newlines Removed support for anything but OpenSSL 1.1.1 or newer. Fixed executable bits for /usr/bin/idle*. Improve python reproducible builds.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
Low
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
Low
Attack Vector
Network
Attack Complexity
High
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-06-04 CVE Reserved
  • 2024-06-27 CVE Published
  • 2025-10-09 CVE Updated
  • 2025-10-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 < 3.9.24
Search vendor "Python Software Foundation" for product "CPython" and version " < 3.9.24"
en
Affected