python3/SOURCES/00354-cve-2020-26116-http-request-method-crlf-injection-in-httplib.patch
2021-09-10 02:27:48 +00:00

74 lines
2.6 KiB
Diff

diff --git a/Lib/http/client.py b/Lib/http/client.py
index f0d2642..0a044e9 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -151,6 +151,10 @@ _contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f]')
# _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$")
# We are more lenient for assumed real world compatibility purposes.
+# These characters are not allowed within HTTP method names
+# to prevent http header injection.
+_contains_disallowed_method_pchar_re = re.compile('[\x00-\x1f]')
+
# We always set the Content-Length header for these methods because some
# servers will otherwise respond with a 411
_METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'}
@@ -1117,6 +1121,8 @@ class HTTPConnection:
else:
raise CannotSendRequest(self.__state)
+ self._validate_method(method)
+
# Save the method we use, we need it later in the response phase
self._method = method
if not url:
@@ -1207,6 +1213,15 @@ class HTTPConnection:
# For HTTP/1.0, the server will assume "not chunked"
pass
+ def _validate_method(self, method):
+ """Validate a method name for putrequest."""
+ # prevent http header injection
+ match = _contains_disallowed_method_pchar_re.search(method)
+ if match:
+ raise ValueError(
+ f"method can't contain control characters. {method!r} "
+ f"(found at least {match.group()!r})")
+
def putheader(self, header, *values):
"""Send a request header line to the server.
diff --git a/Lib/test/test_httplib.py b/Lib/test/test_httplib.py
index 5795b7a..af0350f 100644
--- a/Lib/test/test_httplib.py
+++ b/Lib/test/test_httplib.py
@@ -359,6 +359,28 @@ class HeaderTests(TestCase):
self.assertEqual(lines[2], "header: Second: val")
+class HttpMethodTests(TestCase):
+ def test_invalid_method_names(self):
+ methods = (
+ 'GET\r',
+ 'POST\n',
+ 'PUT\n\r',
+ 'POST\nValue',
+ 'POST\nHOST:abc',
+ 'GET\nrHost:abc\n',
+ 'POST\rRemainder:\r',
+ 'GET\rHOST:\n',
+ '\nPUT'
+ )
+
+ for method in methods:
+ with self.assertRaisesRegex(
+ ValueError, "method can't contain control characters"):
+ conn = client.HTTPConnection('example.com')
+ conn.sock = FakeSocket(None)
+ conn.request(method=method, url="/")
+
+
class TransferEncodingTest(TestCase):
expected_body = b"It's just a flesh wound"