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add exclusion patterns for tarfile-extractall-traversal #72

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add exclusion patterns for tarfile-extractall-traversal #72

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37 changes: 30 additions & 7 deletions python/tarfile-extractall-traversal.py
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Original file line number Diff line number Diff line change
Expand Up @@ -2,11 +2,9 @@
import tarfile

def get_parser():
parser = argparse.ArgumentParser(description='Process zip files.')
parser.add_argument('--path', type=str, required=True,
help='Path to zip file')
parser.add_argument('--save-path', type=str, required=True,
help='Output path')
parser = argparse.ArgumentParser(description="Process tar files.")
parser.add_argument("--path", type=str, required=True, help="Path to tar file")
parser.add_argument("--save-path", type=str, required=True, help="Output path")
return parser


Expand All @@ -17,14 +15,12 @@ def extract_1(args):
with tarfile.open(path) as f:
f.extractall(save_path)


def extract_2(args):
path = args.path
save_path = args.save_path
# ruleid: tarfile-extractall-traversal
tarfile.open(path).extractall(save_path)


def extract_3(args):
path = args.path
save_path = args.save_path
Expand All @@ -33,25 +29,49 @@ def extract_3(args):
tf.extractall(save_path)

def extract_4(args, tarobj):
save_path = args.save_path
# ruleid: tarfile-extractall-traversal
tf = tarfile.open(mode='r', fileobj=None)
tf.extractall(save_path)

def extract_5(args, tarobj):
save_path = args.save_path
# ok: tarfile-extractall-traversal
tf = tarfile.open(mode='r', fileobj=None)
tf.extractall(save_path, members=safu_members())

def extract_6(args, tarobj):
save_path = args.save_path
# ok: tarfile-extractall-traversal
tf = tarfile.open(mode='r', fileobj=None)
tf.extractall(members=safu_members(), numeric_owner=True, path=save_path)

def extract_7(args, tarobj):
save_path = args.save_path
# todoruleid: tarfile-extractall-traversal
tf = tarfile.open(mode='r', fileobj=None)
tf.extractall(members=None, numeric_owner=True, path=save_path)

def extract_8(args):
path = args.path
save_path = args.save_path
# ok: tarfile-extractall-traversal
with tarfile.open(path) as f:
f.extractall(save_path, filter='data')

def extract_9(args):
path = args.path
save_path = args.save_path
# ok: tarfile-extractall-traversal
tarfile.open(path).extractall(save_path, filter='data')

def extract_10(args):
path = args.path
save_path = args.save_path
# ok: tarfile-extractall-traversal
tf = tarfile.open(path)
tf.extractall(save_path, filter='data')

def run():
parser = get_parser()
args = parser.parse_args()
Expand All @@ -62,6 +82,9 @@ def run():
extract_5(args)
extract_6(args)
extract_7(args)
extract_8(args)
extract_9(args)
extract_10(args)


if __name__ == '__main__':
Expand Down
10 changes: 10 additions & 0 deletions python/tarfile-extractall-traversal.yaml
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Expand Up @@ -39,3 +39,13 @@ rules:
$TAR = tarfile.open(...)
...
$TAR.extractall(..., members=$MEMBERS, ...)
- pattern-not: |
with tarfile.open(...) as $TAR:
...
$TAR.extractall(..., filter=$FILTER, ...)
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@Cireo Cireo Dec 28, 2024

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per https://docs.python.org/3/library/tarfile.html#default-named-filters we may still want to have failing behavior if filter is 'fully_trusted', or None prior to 3.14, but at least this forces it to be explicit

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@mschwager mschwager Jan 6, 2025

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Yes, I agree. I think we should still detect cases where filter is set to "fully_trusted", "tar", or None. Since the default will be "data" in Python 3.14 I think that's a reasonable acknowledgment that even "tar" has some security concerns. For example, it allows links to absolute paths or paths outside of the destination.

- pattern-not: |
tarfile.open(...).extractall(..., filter=$FILTER, ...)
- pattern-not: |
$TAR = tarfile.open(...)
...
$TAR.extractall(..., filter=$FILTER, ...)
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