Python CPython Mimetypes MemoryError on Startup via Writable File Locs Windows
CVE-2024-3220 Published on February 14, 2025
Default mimetype known files writeable on Windows
There is a defect in the CPython standard library module mimetypes where on Windows the default list of known file locations are writable meaning other users can create invalid files to cause MemoryError to be raised on Python runtime startup or have file extensions be interpreted as the incorrect file type.
This defect is caused by the default locations of Linux and macOS platforms (such as /etc/mime.types) also being used on Windows, where they are user-writable locations (C:\etc\mime.types).
To work-around this issue a user can call mimetypes.init() with an empty list ([]) on Windows platforms to avoid using the default list of known file locations.
Vulnerability Analysis
CVE-2024-3220 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is an Untrusted Path Vulnerability?
The application searches for critical resources using an externally-supplied search path that can point to resources that are not under the application's direct control.
CVE-2024-3220 has been classified to as an Untrusted Path vulnerability or weakness.
Products Associated with CVE-2024-3220
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Affected Versions
Python Software Foundation CPython:- Before 3.14.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.