CVE-2020-15523 : Security Advisory and Response

In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4rc1, and 3.9 through 3.9.0b4 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). Note that this issue cannot occur when using python.exe from a standard (non-embedded) Python installation on Windows.

Understanding CVE-2020-15523

This CVE highlights a vulnerability in Python versions running on Windows that could lead to the misuse of python3.dll in embedded CPython applications.

What is CVE-2020-15523?

CVE-2020-15523 is a security vulnerability found in various Python versions on Windows systems, allowing for the potential misuse of python3.dll in embedded CPython applications.

The Impact of CVE-2020-15523

The exploitation of this vulnerability could result in malicious actors using a Trojan horse python3.dll in scenarios where CPython is integrated into native applications on Windows.

Technical Details of CVE-2020-15523

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The issue arises from python3X.dll utilizing an incorrect search path for python3.dll loading after Py_SetPath has been employed, potentially leading to a security breach.

Affected Systems and Versions

Python 3.6 through 3.6.10
Python 3.7 through 3.7.8
Python 3.8 through 3.8.4rc1
Python 3.9 through 3.9.0b4

Exploitation Mechanism

The vulnerability can be exploited when CPython is embedded in a native application on Windows, allowing for the misuse of python3.dll.

Mitigation and Prevention

Protecting systems from CVE-2020-15523 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Python to the latest patched version to mitigate the vulnerability.
Avoid embedding CPython in native applications if possible.

Long-Term Security Practices

Regularly monitor for Python security updates and apply them promptly.
Implement secure coding practices to prevent similar vulnerabilities in the future.

Patching and Updates

Ensure that all Python installations on Windows systems are updated to versions where this vulnerability has been patched.