From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Mon, 12 Aug 2024 02:35:17 +0200 Subject: [PATCH] 00436: [CVE-2024-8088] gh-122905: Sanitize names in zipfile.Path. --- Lib/test/test_zipfile/_path/test_path.py | 17 +++++ Lib/zipfile/_path/__init__.py | 64 ++++++++++++++++++- ...-08-11-14-08-04.gh-issue-122905.7tDsxA.rst | 1 + 3 files changed, 81 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2024-08-11-14-08-04.gh-issue-122905.7tDsxA.rst diff --git a/Lib/test/test_zipfile/_path/test_path.py b/Lib/test/test_zipfile/_path/test_path.py index 06d5aab69b..90885dbbe3 100644 --- a/Lib/test/test_zipfile/_path/test_path.py +++ b/Lib/test/test_zipfile/_path/test_path.py @@ -577,3 +577,20 @@ def test_getinfo_missing(self, alpharep): zipfile.Path(alpharep) with self.assertRaises(KeyError): alpharep.getinfo('does-not-exist') + + def test_malformed_paths(self): + """ + Path should handle malformed paths. + """ + data = io.BytesIO() + zf = zipfile.ZipFile(data, "w") + zf.writestr("/one-slash.txt", b"content") + zf.writestr("//two-slash.txt", b"content") + zf.writestr("../parent.txt", b"content") + zf.filename = '' + root = zipfile.Path(zf) + assert list(map(str, root.iterdir())) == [ + 'one-slash.txt', + 'two-slash.txt', + 'parent.txt', + ] diff --git a/Lib/zipfile/_path/__init__.py b/Lib/zipfile/_path/__init__.py index 78c413563b..42f9fded21 100644 --- a/Lib/zipfile/_path/__init__.py +++ b/Lib/zipfile/_path/__init__.py @@ -83,7 +83,69 @@ def __setstate__(self, state): super().__init__(*args, **kwargs) -class CompleteDirs(InitializedState, zipfile.ZipFile): +class SanitizedNames: + """ + ZipFile mix-in to ensure names are sanitized. + """ + + def namelist(self): + return list(map(self._sanitize, super().namelist())) + + @staticmethod + def _sanitize(name): + r""" + Ensure a relative path with posix separators and no dot names. + + Modeled after + https://github.com/python/cpython/blob/bcc1be39cb1d04ad9fc0bd1b9193d3972835a57c/Lib/zipfile/__init__.py#L1799-L1813 + but provides consistent cross-platform behavior. + + >>> san = SanitizedNames._sanitize + >>> san('/foo/bar') + 'foo/bar' + >>> san('//foo.txt') + 'foo.txt' + >>> san('foo/.././bar.txt') + 'foo/bar.txt' + >>> san('foo../.bar.txt') + 'foo../.bar.txt' + >>> san('\\foo\\bar.txt') + 'foo/bar.txt' + >>> san('D:\\foo.txt') + 'D/foo.txt' + >>> san('\\\\server\\share\\file.txt') + 'server/share/file.txt' + >>> san('\\\\?\\GLOBALROOT\\Volume3') + '?/GLOBALROOT/Volume3' + >>> san('\\\\.\\PhysicalDrive1\\root') + 'PhysicalDrive1/root' + + Retain any trailing slash. + >>> san('abc/') + 'abc/' + + Raises a ValueError if the result is empty. + >>> san('../..') + Traceback (most recent call last): + ... + ValueError: Empty filename + """ + + def allowed(part): + return part and part not in {'..', '.'} + + # Remove the drive letter. + # Don't use ntpath.splitdrive, because that also strips UNC paths + bare = re.sub('^([A-Z]):', r'\1', name, flags=re.IGNORECASE) + clean = bare.replace('\\', '/') + parts = clean.split('/') + joined = '/'.join(filter(allowed, parts)) + if not joined: + raise ValueError("Empty filename") + return joined + '/' * name.endswith('/') + + +class CompleteDirs(InitializedState, SanitizedNames, zipfile.ZipFile): """ A ZipFile subclass that ensures that implied directories are always included in the namelist. diff --git a/Misc/NEWS.d/next/Library/2024-08-11-14-08-04.gh-issue-122905.7tDsxA.rst b/Misc/NEWS.d/next/Library/2024-08-11-14-08-04.gh-issue-122905.7tDsxA.rst new file mode 100644 index 0000000000..1be44c906c --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-08-11-14-08-04.gh-issue-122905.7tDsxA.rst @@ -0,0 +1 @@ +:class:`zipfile.Path` objects now sanitize names from the zipfile.