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wiredfoolhugovk
wiredfool
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hugovk
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Fix DOS in PSDImagePlugin -- CVE-2021-28675
* PSDImagePlugin did not sanity check the number of input layers and vs the size of the data block, this could lead to a DOS on Image.open prior to Image.load. * This issue dates to the PIL fork
1 parent ba65f0b commit 22e9bee

11 files changed

Lines changed: 55 additions & 17 deletions

‎Tests/images/timeout-1ee28a249896e05b83840ae8140622de8e648ba9.psd‎

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‎Tests/images/timeout-598843abc37fc080ec36a2699ebbd44f795d3a6f.psd‎

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‎Tests/images/timeout-c8efc3fded6426986ba867a399791bae544f59bc.psd‎

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‎Tests/images/timeout-dedc7a4ebd856d79b4359bbcc79e8ef231ce38f6.psd‎

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‎Tests/test_decompression_bomb.py‎

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@@ -52,6 +52,7 @@ def test_exception(self):
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with Image.open(TEST_FILE):
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pass
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@pytest.mark.xfail(reason="different exception")
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def test_exception_ico(self):
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with pytest.raises(Image.DecompressionBombError):
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with Image.open("Tests/images/decompression_bomb.ico"):

‎Tests/test_file_apng.py‎

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@@ -312,7 +312,7 @@ def open_frames_zero_default():
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exception = e
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assert exception is None
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with pytest.raises(SyntaxError):
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with pytest.raises(OSError):
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with Image.open("Tests/images/apng/syntax_num_frames_high.png") as im:
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im.seek(im.n_frames - 1)
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im.load()

‎Tests/test_file_blp.py‎

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@@ -1,4 +1,5 @@
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from PIL import Image
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import pytest
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from .helper import assert_image_equal_tofile
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‎Tests/test_file_psd.py‎

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@@ -130,3 +130,18 @@ def test_combined_larger_than_size():
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with pytest.raises(OSError):
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with Image.open("Tests/images/combined_larger_than_size.psd"):
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pass
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@pytest.mark.parametrize(
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"test_file,raises",
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[
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("Tests/images/timeout-1ee28a249896e05b83840ae8140622de8e648ba9.psd", Image.UnidentifiedImageError),
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("Tests/images/timeout-598843abc37fc080ec36a2699ebbd44f795d3a6f.psd", Image.UnidentifiedImageError),
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("Tests/images/timeout-c8efc3fded6426986ba867a399791bae544f59bc.psd", OSError),
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("Tests/images/timeout-dedc7a4ebd856d79b4359bbcc79e8ef231ce38f6.psd", OSError),
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],
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)
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def test_crashes(test_file, raises):
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with open(test_file, "rb") as f:
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with pytest.raises(raises):
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with Image.open(f):
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pass

‎Tests/test_file_tiff.py‎

Lines changed: 4 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -625,9 +625,10 @@ def test_close_on_load_nonexclusive(self, tmp_path):
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)
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def test_string_dimension(self):
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# Assert that an error is raised if one of the dimensions is a string
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with pytest.raises(ValueError):
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with Image.open("Tests/images/string_dimension.tiff"):
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pass
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with pytest.raises(OSError):
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with Image.open("Tests/images/string_dimension.tiff") as im:
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im.load()
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@pytest.mark.skipif(not is_win32(), reason="Windows only")

‎src/PIL/ImageFile.py‎

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Original file line numberDiff line numberDiff line change
@@ -545,22 +545,32 @@ def _safe_read(fp, size):
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:param fp: File handle. Must implement a <b>read</b> method.
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:param size: Number of bytes to read.
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:returns: A string containing up to <i>size</i> bytes of data.
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:returns: A string containing <i>size</i> bytes of data.
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Raises an OSError if the file is truncated and the read can not be completed
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"""
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if size <= 0:
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return b""
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if size <= SAFEBLOCK:
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return fp.read(size)
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data = fp.read(size)
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if len(data) < size:
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raise OSError("Truncated File Read")
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return data
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data = []
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while size > 0:
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block = fp.read(min(size, SAFEBLOCK))
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if not block:
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break
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data.append(block)
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size -= len(block)
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if sum(len(d) for d in data) < size:
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raise OSError("Truncated File Read")
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return b"".join(data)
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class PyCodecState:
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def __init__(self):
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self.xsize = 0

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