MIME mapping corruption via writable default search paths
Published Feb 14, 2025 · Updated Mar 14, 2025
Untrusted search path handling in CPython before 3.14.0 allows local users on Windows to alter MIME mappings or trigger a MemoryError. The mimetypes.init function treats Unix-style entries in knownfiles as Windows paths and reads matching user-writable files without verifying their trust. Exploitation requires access to create a default file such as C:\etc\mime.types, after which a targeted Python process can misclassify extensions or stop during initialization.
Summary
What happened
Untrusted search path handling in CPython before 3.14.0 allows local users on Windows to alter MIME mappings or trigger a MemoryError. The mimetypes.init function treats Unix-style entries in knownfiles as Windows paths and reads matching user-writable files without verifying their trust. Exploitation requires access to create a default file such as C:\etc\mime.types, after which a targeted Python process can misclassify extensions or stop during initialization.
The record
- CVE
- CVE-2024-3220
- Published
- Feb 14, 2025
- Updated
- Mar 14, 2025
- Vendor
- Python Software Foundation
- Product
- CPython
- Classifications
- CWE-426, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 14, 2025CVE publishedPublication date reported by the CVE source.
- Mar 14, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <3.14.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
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Your stack
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