CVE-2025-4330: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in Python Software Foundation CPython
Allows the extraction filter to be ignored, allowing symlink targets to point outside the destination directory, and the modification of some file metadata. 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 in CPython's tarfile module (CVE-2025-4330) involves improper limitation of a pathname to a restricted directory (CWE-22). It allows attackers to bypass the extraction filter, causing symlink targets within tar archives to point outside the extraction directory, potentially modifying file metadata outside the intended scope. The issue affects the use of TarFile.extractall() and TarFile.extract() when the filter parameter is set to "data" or "tar", including the default filter in Python 3.14 and later. This could lead to unauthorized file modifications during archive extraction.
Potential Impact
The vulnerability allows an attacker to bypass pathname restrictions during tar archive extraction, enabling symlink targets to reference locations outside the intended extraction directory. This can result in unauthorized modification of file metadata outside the target directory. There is no direct impact on confidentiality or availability, but integrity is impacted. Source distributions are less affected due to existing arbitrary code execution risks during build processes.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid extracting untrusted tar archives using TarFile.extractall() or TarFile.extract() with the filter parameter set to "data" or "tar". Exercise caution when installing source distributions containing suspicious symbolic links. Monitor the official Python Software Foundation advisories for updates and patches.
CVE-2025-4330: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in Python Software Foundation CPython
Description
Allows the extraction filter to be ignored, allowing symlink targets to point outside the destination directory, and the modification of some file metadata. 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.
CVSS v3.1
Score 7.5high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in CPython's tarfile module (CVE-2025-4330) involves improper limitation of a pathname to a restricted directory (CWE-22). It allows attackers to bypass the extraction filter, causing symlink targets within tar archives to point outside the extraction directory, potentially modifying file metadata outside the intended scope. The issue affects the use of TarFile.extractall() and TarFile.extract() when the filter parameter is set to "data" or "tar", including the default filter in Python 3.14 and later. This could lead to unauthorized file modifications during archive extraction.
Potential Impact
The vulnerability allows an attacker to bypass pathname restrictions during tar archive extraction, enabling symlink targets to reference locations outside the intended extraction directory. This can result in unauthorized modification of file metadata outside the target directory. There is no direct impact on confidentiality or availability, but integrity is impacted. Source distributions are less affected due to existing arbitrary code execution risks during build processes.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid extracting untrusted tar archives using TarFile.extractall() or TarFile.extract() with the filter parameter set to "data" or "tar". Exercise caution when installing source distributions containing suspicious symbolic links. Monitor the official Python Software Foundation advisories for updates and patches.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- PSF
- Date Reserved
- 2025-05-05T15:05:14.302Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 683eff8d182aa0cae27db842
Added to database: 06/03/2025, 13:58:37 UTC
Last enriched: 08/06/2026, 13:55:33 UTC
Last updated: 09/10/2026, 19:36:50 UTC
Views: 185
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