CVE-2007-4559 Patch

enot/pac_cache/cache.py

@@ -70,7 +70,29 @@ def unpackage(self, package: Package):  # TODO move me to package? use current d
         ensure_empty(unpack_dir)
         info('Extract ' + enotpack)
         with tarfile.open(enotpack) as pack:
-            pack.extractall(unpack_dir)
+
+            import os
+
+            def is_within_directory(directory, target):
+
+                abs_directory = os.path.abspath(directory)
+                abs_target = os.path.abspath(target)
+
+                prefix = os.path.commonprefix([abs_directory, abs_target])
+
+                return prefix == abs_directory
+
+            def safe_extract(tar, path=".", members=None, *, numeric_owner=False):
+
+                for member in tar.getmembers():
+                    member_path = os.path.join(path, member.name)
+                    if not is_within_directory(path, member_path):
+                        raise Exception("Attempted Path Traversal in Tar File")
+
+                tar.extractall(path, members, numeric_owner=numeric_owner) 
+
+
+            safe_extract(pack, unpack_dir)
         package.path = unpack_dir  # update path pointer
         copy_file(enotpack, join(unpack_dir, package.name + '.ep'))
 

enot/utils/file_utils.py

@@ -34,7 +34,26 @@ def tar(path: str, dirs: list, dst: str):
 
 def untar(path: str, dst: str):
     with tarfile.open(path, 'r') as archive:
-        archive.extractall(dst)
+        def is_within_directory(directory, target):
+
+            abs_directory = os.path.abspath(directory)
+            abs_target = os.path.abspath(target)
+
+            prefix = os.path.commonprefix([abs_directory, abs_target])
+
+            return prefix == abs_directory
+
+        def safe_extract(tar, path=".", members=None, *, numeric_owner=False):
+
+            for member in tar.getmembers():
+                member_path = os.path.join(path, member.name)
+                if not is_within_directory(path, member_path):
+                    raise Exception("Attempted Path Traversal in Tar File")
+
+            tar.extractall(path, members, numeric_owner=numeric_owner) 
+
+
+        safe_extract(archive, dst)
 
 
 # TODO catch read errors