Merge pull request from GHSA-g4mx-q9vg-27p4

dummyserver/handlers.py

@@ -186,6 +186,8 @@ def redirect(self, request):
         status = request.params.get("status", "303 See Other")
         if len(status) == 3:
             status = "%s Redirect" % status.decode("latin-1")
+        elif isinstance(status, bytes):
+            status = status.decode("latin-1")
 
         headers = [("Location", target)]
         return Response(status=status, headers=headers)
@@ -264,6 +266,11 @@ def encodingrequest(self, request):
     def headers(self, request):
         return Response(json.dumps(dict(request.headers)))
 
+    def headers_and_params(self, request):
+        return Response(
+            json.dumps({"headers": dict(request.headers), "params": request.params})
+        )
+
     def successful_retry(self, request):
         """Handler which will return an error and then success
 

src/urllib3/_collections.py

@@ -268,6 +268,24 @@ def getlist(self, key, default=__marker):
         else:
             return vals[1:]
 
+    def _prepare_for_method_change(self):
+        """
+        Remove content-specific header fields before changing the request
+        method to GET or HEAD according to RFC 9110, Section 15.4.
+        """
+        content_specific_headers = [
+            "Content-Encoding",
+            "Content-Language",
+            "Content-Location",
+            "Content-Type",
+            "Content-Length",
+            "Digest",
+            "Last-Modified",
+        ]
+        for header in content_specific_headers:
+            self.discard(header)
+        return self
+
     # Backwards compatibility for httplib
     getheaders = getlist
     getallmatchingheaders = getlist

src/urllib3/connectionpool.py

@@ -9,6 +9,7 @@
 from socket import error as SocketError
 from socket import timeout as SocketTimeout
 
+from ._collections import HTTPHeaderDict
 from .connection import (
     BaseSSLError,
     BrokenPipeError,
@@ -843,7 +844,11 @@ def _is_ssl_error_message_from_http_proxy(ssl_error):
         redirect_location = redirect and response.get_redirect_location()
         if redirect_location:
             if response.status == 303:
+                # Change the method according to RFC 9110, Section 15.4.4.
                 method = "GET"
+                # And lose the body not to transfer anything sensitive.
+                body = None
+                headers = HTTPHeaderDict(headers)._prepare_for_method_change()
 
             try:
                 retries = retries.increment(method, url, response=response, _pool=self)

src/urllib3/poolmanager.py

@@ -4,7 +4,7 @@
 import functools
 import logging
 
-from ._collections import RecentlyUsedContainer
+from ._collections import HTTPHeaderDict, RecentlyUsedContainer
 from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool, port_by_scheme
 from .exceptions import (
     LocationValueError,
@@ -382,9 +382,12 @@ def urlopen(self, method, url, redirect=True, **kw):
         # Support relative URLs for redirecting.
         redirect_location = urljoin(url, redirect_location)
 
-        # RFC 7231, Section 6.4.4
         if response.status == 303:
+            # Change the method according to RFC 9110, Section 15.4.4.
             method = "GET"
+            # And lose the body not to transfer anything sensitive.
+            kw["body"] = None
+            kw["headers"] = HTTPHeaderDict(kw["headers"])._prepare_for_method_change()
 
         retries = kw.get("retries")
         if not isinstance(retries, Retry):

test/with_dummyserver/test_connectionpool.py

@@ -464,6 +464,17 @@ def test_redirect(self):
             assert r.status == 200
             assert r.data == b"Dummy server!"
 
+    def test_303_redirect_makes_request_lose_body(self):
+        with HTTPConnectionPool(self.host, self.port) as pool:
+            response = pool.request(
+                "POST",
+                "/redirect",
+                fields={"target": "/headers_and_params", "status": "303 See Other"},
+            )
+        data = json.loads(response.data)
+        assert data["params"] == {}
+        assert "Content-Type" not in HTTPHeaderDict(data["headers"])
+
     def test_bad_connect(self):
         with HTTPConnectionPool("badhost.invalid", self.port) as pool:
             with pytest.raises(MaxRetryError) as e:

test/with_dummyserver/test_poolmanager.py

@@ -5,6 +5,7 @@
 
 from dummyserver.server import HAS_IPV6
 from dummyserver.testcase import HTTPDummyServerTestCase, IPv6HTTPDummyServerTestCase
+from urllib3._collections import HTTPHeaderDict
 from urllib3.connectionpool import port_by_scheme
 from urllib3.exceptions import MaxRetryError, URLSchemeUnknown
 from urllib3.poolmanager import PoolManager
@@ -236,6 +237,20 @@ def test_redirect_without_preload_releases_connection(self):
             assert r._pool.num_connections == 1
             assert len(http.pools) == 1
 
+    def test_303_redirect_makes_request_lose_body(self):
+        with PoolManager() as http:
+            response = http.request(
+                "POST",
+                "%s/redirect" % self.base_url,
+                fields={
+                    "target": "%s/headers_and_params" % self.base_url,
+                    "status": "303 See Other",
+                },
+            )
+        data = json.loads(response.data)
+        assert data["params"] == {}
+        assert "Content-Type" not in HTTPHeaderDict(data["headers"])
+
     def test_unknown_scheme(self):
         with PoolManager() as http:
             unknown_scheme = "unknown"