diff --git a/sanic/__version__.py b/sanic/__version__.py index faa7ddb987..9bccec66fe 100644 --- a/sanic/__version__.py +++ b/sanic/__version__.py @@ -1 +1 @@ -__version__ = "20.12.6" +__version__ = "20.12.7" diff --git a/sanic/static.py b/sanic/static.py index 0a75d9dceb..875fa3df44 100644 --- a/sanic/static.py +++ b/sanic/static.py @@ -1,7 +1,6 @@ from functools import partial, wraps from mimetypes import guess_type -from os import path -from re import sub +from os import path, sep from time import gmtime, strftime from urllib.parse import unquote @@ -26,28 +25,33 @@ async def _static_request_handler( content_type=None, file_uri=None, ): - # Using this to determine if the URL is trying to break out of the path - # served. os.path.realpath seems to be very slow - if file_uri and "../" in file_uri: - raise InvalidUsage("Invalid URL") # Merge served directory and requested file if provided - # Strip all / that in the beginning of the URL to help prevent python - # from herping a derp and treating the uri as an absolute path - root_path = file_path = file_or_directory + root_path = file_path = path.abspath(unquote(file_or_directory)) + if file_uri: - file_path = path.join(file_or_directory, sub("^[/]*", "", file_uri)) + # Strip all / that in the beginning of the URL to help prevent + # python from herping a derp and treating the uri as an + # absolute path + unquoted_file_uri = unquote(file_uri).lstrip("/") + + segments = unquoted_file_uri.split("/") + if ".." in segments or any(sep in segment for segment in segments): + raise InvalidUsage("Invalid URL") + + file_path = path.join(file_or_directory, unquoted_file_uri) + file_path = path.abspath(file_path) - # URL decode the path sent by the browser otherwise we won't be able to - # match filenames which got encoded (filenames with spaces etc) - file_path = path.abspath(unquote(file_path)) - if not file_path.startswith(path.abspath(unquote(root_path))): + if not file_path.startswith(root_path): error_logger.exception( f"File not found: path={file_or_directory}, " f"relative_url={file_uri}" ) raise FileNotFound( - "File not found", path=file_or_directory, relative_url=file_uri + "File not found", + path=file_or_directory, + relative_url=file_uri, ) + try: headers = {} # Check if the client has been sent this file before diff --git a/tests/test_static.py b/tests/test_static.py index 91635a4551..e5ecd673e5 100644 --- a/tests/test_static.py +++ b/tests/test_static.py @@ -1,10 +1,14 @@ import inspect import os +import sys +from pathlib import Path from time import gmtime, strftime import pytest +from sanic.app import Sanic + @pytest.fixture(scope="module") def static_file_directory(): @@ -15,6 +19,22 @@ def static_file_directory(): return static_directory +@pytest.fixture(scope="module") +def double_dotted_directory_file(static_file_directory: str): + """Generate double dotted directory and its files""" + if sys.platform == "win32": + raise Exception("Windows doesn't support double dotted directories") + + file_path = Path(static_file_directory) / "dotted.." / "dot.txt" + double_dotted_dir = file_path.parent + Path.mkdir(double_dotted_dir, exist_ok=True) + with open(file_path, "w") as f: + f.write("DOT\n") + yield file_path + Path.unlink(file_path) + Path.rmdir(double_dotted_dir) + + def get_file_path(static_file_directory, file_name): return os.path.join(static_file_directory, file_name) @@ -374,3 +394,41 @@ def test_static_name(app, static_file_directory, static_name, file_name): request, response = app.test_client.get(f"/static/{file_name}") assert response.status == 200 + + +@pytest.mark.skipif( + sys.platform == "win32", + reason="Windows does not support double dotted directories", +) +def test_dotted_dir_ok( + app: Sanic, static_file_directory: str, double_dotted_directory_file: Path +): + app.static("/foo", static_file_directory) + url = ( + "/foo" + + str(double_dotted_directory_file)[len(static_file_directory) :] + ) + _, response = app.test_client.get(url) + assert response.status == 200 + assert response.body == b"DOT\n" + + +def test_breakout(app: Sanic, static_file_directory: str): + app.static("/foo", static_file_directory) + + _, response = app.test_client.get("/foo/..%2Fstatic/test.file") + assert response.status == 400 + + +@pytest.mark.skipif( + sys.platform != "win32", reason="Block backslash on Windows only" +) +def test_double_backslash_prohibited_on_win32( + app: Sanic, static_file_directory: str +): + app.static("/foo", static_file_directory) + + _, response = app.test_client.get("/foo/static/..\\static/test.file") + assert response.status == 400 + _, response = app.test_client.get("/foo/static\\../static/test.file") + assert response.status == 400