CVE-2025-4517: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in Python Software Foundation CPython
Allows arbitrary filesystem writes outside the extraction directory during extraction with filter="data". You are affected by this vulnerability if using the tarfile module to extract untrusted tar archives using TarFile.extractall() or TarFile.extract() using the filter= parameter with a value of "data" or "tar". See the tarfile extraction filters documentation https://docs.python.org/3/library/tarfile.html#tarfile-extraction-filter for more information. Note that for Python 3.14 or later the default value of filter= changed from "no filtering" to `"data", so if you are relying on this new default behavior then your usage is also affected. Note that none of these vulnerabilities significantly affect the installation of source distributions which are tar archives as source distributions already allow arbitrary code execution during the build process. However when evaluating source distributions it's important to avoid installing source distributions with suspicious links.
AI Analysis
Technical Summary
This vulnerability (CWE-22) in the Python Software Foundation's CPython tarfile module permits attackers to perform path traversal attacks during extraction of tar archives when using the filter parameter set to "data" or "tar". This results in arbitrary filesystem writes outside the extraction directory, potentially leading to code execution or system compromise. The issue affects multiple Python versions up to 3.14.0a1, with a critical CVSS 3.1 score of 9.4 indicating high impact on confidentiality and integrity. The vulnerability arises because the pathname limitation is improperly enforced during extraction filtering.
Potential Impact
Successful exploitation allows an attacker to write files to arbitrary locations on the filesystem outside the intended extraction directory. This can lead to arbitrary code execution or system compromise if malicious tar archives are extracted without proper validation. The vulnerability affects all users extracting untrusted tar archives using the vulnerable tarfile module with the specified filter settings. Source distribution installations are less impacted due to existing risks during build processes.
Mitigation Recommendations
Patch status is not yet confirmed — check the Python Software Foundation advisory for current remediation guidance. Until an official fix is released, avoid extracting untrusted tar archives using TarFile.extractall() or TarFile.extract() with the filter parameter set to "data" or "tar". Consider using alternative extraction methods or validating tar archive contents before extraction. Monitor the official Python tarfile extraction filters documentation and security advisories for updates and patches.
CVE-2025-4517: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in Python Software Foundation CPython
Description
Allows arbitrary filesystem writes outside the extraction directory during extraction with filter="data". You are affected by this vulnerability if using the tarfile module to extract untrusted tar archives using TarFile.extractall() or TarFile.extract() using the filter= parameter with a value of "data" or "tar". See the tarfile extraction filters documentation https://docs.python.org/3/library/tarfile.html#tarfile-extraction-filter for more information. Note that for Python 3.14 or later the default value of filter= changed from "no filtering" to `"data", so if you are relying on this new default behavior then your usage is also affected. Note that none of these vulnerabilities significantly affect the installation of source distributions which are tar archives as source distributions already allow arbitrary code execution during the build process. However when evaluating source distributions it's important to avoid installing source distributions with suspicious links.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-22) in the Python Software Foundation's CPython tarfile module permits attackers to perform path traversal attacks during extraction of tar archives when using the filter parameter set to "data" or "tar". This results in arbitrary filesystem writes outside the extraction directory, potentially leading to code execution or system compromise. The issue affects multiple Python versions up to 3.14.0a1, with a critical CVSS 3.1 score of 9.4 indicating high impact on confidentiality and integrity. The vulnerability arises because the pathname limitation is improperly enforced during extraction filtering.
Potential Impact
Successful exploitation allows an attacker to write files to arbitrary locations on the filesystem outside the intended extraction directory. This can lead to arbitrary code execution or system compromise if malicious tar archives are extracted without proper validation. The vulnerability affects all users extracting untrusted tar archives using the vulnerable tarfile module with the specified filter settings. Source distribution installations are less impacted due to existing risks during build processes.
Mitigation Recommendations
Patch status is not yet confirmed — check the Python Software Foundation advisory for current remediation guidance. Until an official fix is released, avoid extracting untrusted tar archives using TarFile.extractall() or TarFile.extract() with the filter parameter set to "data" or "tar". Consider using alternative extraction methods or validating tar archive contents before extraction. Monitor the official Python tarfile extraction filters documentation and security advisories for updates and patches.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- PSF
- Date Reserved
- 2025-05-09T15:05:07.139Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 683eff8d182aa0cae27db844
Added to database: 6/3/2025, 1:58:37 PM
Last enriched: 4/22/2026, 5:42:41 AM
Last updated: 5/9/2026, 4:05:58 AM
Views: 94
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