निकालने वाले फ़िल्टर को बाईपास करना, निकालने वाले निर्देशिका के बाहर लिंक करने के लिए

An attacker can exploit this vulnerability by crafting a malicious tar archive that contains symlinks pointing outside the intended extraction directory. When TarFile.extractall() or TarFile.extract() is called with the filter parameter set to 'data' or 'tar', the extraction filter is bypassed, allowing the symlinks to be resolved and files to be written to arbitrary locations on the system. This could allow an attacker to overwrite critical system files, execute arbitrary code, or gain unauthorized access to sensitive data. The potential impact is significant, especially in environments where untrusted tar archives are routinely processed.

Systems that automatically process untrusted tar archives, such as build servers, data ingestion pipelines, or web applications that allow users to upload archives, are particularly at risk. Environments using older Python versions (3.10.0 - 3.14.0b3) are also vulnerable. Shared hosting environments where multiple users can upload files are also at increased risk.

• python / server:

find / -name '*.tar.gz' -o -name '*.tar.bz2' -o -name '*.tar'

• python / server:

journalctl -u python3 | grep "TarFile.extractall" | grep "filter="

• python / server:

ps aux | grep "TarFile.extractall" | grep "filter="

1. 2025-06-03Disclosure

   disclosure

1. आरक्षित2025-05-05
2. प्रकाशित2025-06-03
3. संशोधित2026-04-21
4. EPSS अद्यतन2026-03-23

The primary mitigation is to upgrade to Python 3.14.0b3 or later, where the default value of the filter parameter has been changed to prevent this bypass. If upgrading is not immediately feasible, consider disabling the use of the filter parameter entirely when extracting untrusted archives. Alternatively, implement strict input validation to ensure that the extracted files are confined to the intended directory. Consider using a WAF or proxy to inspect incoming tar archives for malicious symlinks before processing them. For existing deployments, review code that uses TarFile.extractall() or TarFile.extract() with the filter parameter and implement the recommended mitigations.