CVE-2019-12387 (published 2019-06-10T12:29Z)

In Twisted before 19.2.1, twisted.web did not validate or sanitize URIs or HTTP methods, allowing an attacker to inject invalid characters such as CRLF.

Severity: MEDIUM
CVSS v2 base score: 4.3 (AV:N/AC:M/Au:N/C:N/I:P/A:N)
CVSS v3 base score: 6.1, MEDIUM (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)

Weakness information:
cwe_id: CWE-74
cwe_name: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
description: The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
extended_description: Software or other automated logic has certain assumptions about what constitutes data and control respectively. It is the lack of verification of these assumptions for user-controlled input that leads to injection problems. Injection problems encompass a wide variety of issues -- all mitigated in very different ways and usually attempted in order to alter the control flow of the process. For this reason, the most effective way to discuss these weaknesses is to note the distinct features that classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed.
         

Fix information:
repo_url: https://github.com/twisted/twisted
commit_details: repo_url: https://github.com/twisted/twisted
author: Mark Williams
author_date: 2019-06-05 00:03:37-07:00
msg: Prevent CRLF injections described in CVE-2019-12387

Author: markrwilliams

Reviewers: glyph

Fixes: ticket:9647

Twisted's HTTP client APIs were vulnerable to maliciously constructed
HTTP methods, hosts, and/or paths, URI components such as paths and
query parameters.  These vulnerabilities were beyond the header name
and value injection vulnerabilities addressed in:

https://twistedmatrix.com/trac/ticket/9420
https://github.com/twisted/twisted/pull/999/

The following client APIs will raise a ValueError if given a method,
host, or URI that includes newlines or other disallowed characters:

- twisted.web.client.Agent.request
- twisted.web.client.ProxyAgent.request
- twisted.web.client.Request.__init__
- twisted.web.client.Request.writeTo

ProxyAgent is patched separately from Agent because unlike other
agents (e.g. CookieAgent) it is not implemented as an Agent wrapper.

Request.__init__ checks its method and URI so that errors occur closer
to their originating input.  Request.method and Request.uri are both
public APIs, however, so Request.writeTo (via Request._writeHeaders)
also checks the validity of both before writing anything to the wire.

Additionally, the following deprecated client APIs have also been
patched:

- twisted.web.client.HTTPPageGetter.__init__
- twisted.web.client.HTTPPageDownloader.__init__
- twisted.web.client.HTTPClientFactory.__init__
- twisted.web.client.HTTPClientFactory.setURL
- twisted.web.client.HTTPDownloader.__init__
- twisted.web.client.HTTPDownloader.setURL
- twisted.web.client.getPage
- twisted.web.client.downloadPage

These have been patched prior to their removal so that they won't be
vulnerable in the last Twisted release that includes them.  They
represent a best effort, because testing every combination of these
public APIs would require more code than deprecated APIs warrant.

In all cases URI components, including hostnames, are restricted to
the characters allowed in path components.  This mirrors the CPython
patch (for bpo-30458) that addresses equivalent vulnerabilities:

https://github.com/python/cpython/commit/bb8071a4cae5ab3fe321481dd3d73662ffb26052

HTTP methods, however, are checked against the set of characters
described in RFC-7230.
repository: repo_url: https://github.com/twisted/twisted
repo_name: twisted/twisted
description: Event-driven networking engine written in Python.
repo_language: Python
owner: twisted
file_changes: filename: _newclient.py
change_type: ModificationType.MODIFY
diff: @@ -29,6 +29,8 @@ Various other classes in this module support this usage:
 from __future__ import division, absolute_import
 __metaclass__ = type
 
+import re
+
 from zope.interface import implementer
 
 from twisted.python.compat import networkString
@@ -579,6 +581,74 @@ class HTTPClientParser(HTTPParser):
 
 
 
+_VALID_METHOD = re.compile(
+    br"\A[%s]+\Z" % (
+        bytes().join(
+            (
+                b"!", b"#", b"$", b"%", b"&", b"'", b"*",
+                b"+", b"-", b".", b"^", b"_", b"`", b"|", b"~",
+                b"\x30-\x39",
+                b"\x41-\x5a",
+                b"\x61-\x7A",
+            ),
+        ),
+    ),
+)
+
+
+
+def _ensureValidMethod(method):
+    """
+    An HTTP method is an HTTP token, which consists of any visible
+    ASCII character that is not a delimiter (i.e. one of
+    C{"(),/:;<=>?@[\\]{}}.)
+
+    @param method: the method to check
+    @type method: L{bytes}
+
+    @return: the method if it is valid
+    @rtype: L{bytes}
+
+    @raise ValueError: if the method is not valid
+
+    @see: U{https://tools.ietf.org/html/rfc7230#section-3.1.1},
+        U{https://tools.ietf.org/html/rfc7230#section-3.2.6},
+        U{https://tools.ietf.org/html/rfc5234#appendix-B.1}
+    """
+    if _VALID_METHOD.match(method):
+        return method
+    raise ValueError("Invalid method {!r}".format(method))
+
+
+
+_VALID_URI = re.compile(br'\A[\x21-\x7e]+\Z')
+
+
+
+def _ensureValidURI(uri):
+    """
+    A valid URI cannot contain control characters (i.e., characters
+    between 0-32, inclusive and 127) or non-ASCII characters (i.e.,
+    characters with values between 128-255, inclusive).
+
+    @param uri: the URI to check
+    @type uri: L{bytes}
+
+    @return: the URI if it is valid
+    @rtype: L{bytes}
+
+    @raise ValueError: if the URI is not valid
+
+    @see: U{https://tools.ietf.org/html/rfc3986#section-3.3},
+        U{https://tools.ietf.org/html/rfc3986#appendix-A},
+        U{https://tools.ietf.org/html/rfc5234#appendix-B.1}
+    """
+    if _VALID_URI.match(uri):
+        return uri
+    raise ValueError("Invalid URI {!r}".format(uri))
+
+
+
 @implementer(IClientRequest)
 class Request:
     """
@@ -618,8 +688,8 @@ class Request:
             connection, defaults to C{False}.
         @type persistent: L{bool}
         """
-        self.method = method
-        self.uri = uri
+        self.method = _ensureValidMethod(method)
+        self.uri = _ensureValidURI(uri)
         self.headers = headers
         self.bodyProducer = bodyProducer
         self.persistent = persistent
@@ -664,8 +734,15 @@ class Request:
         # method would probably be good.  It would be nice if this method
         # weren't limited to issuing HTTP/1.1 requests.
         requestLines = []
-        requestLines.append(b' '.join([self.method, self.uri,
-            b'HTTP/1.1\r\n']))
+        requestLines.append(
+            b' '.join(
+                [
+                    _ensureValidMethod(self.method),
+                    _ensureValidURI(self.uri),
+                    b'HTTP/1.1\r\n',
+                ]
+            ),
+        )
         if not self.persistent:
             requestLines.append(b'Connection: close\r\n')
         if TEorCL is not None:

programming_language: Python
filename: client.py
change_type: ModificationType.MODIFY
diff: @@ -47,6 +47,9 @@ from twisted.web.iweb import UNKNOWN_LENGTH, IAgent, IBodyProducer, IResponse
 from twisted.web.http_headers import Headers
 from twisted.logger import Logger
 
+from twisted.web._newclient import _ensureValidURI, _ensureValidMethod
+
+
 
 class PartialDownloadError(error.Error):
     """
@@ -78,11 +81,13 @@ class HTTPPageGetter(http.HTTPClient):
 
     _completelyDone = True
 
-    _specialHeaders = set((b'host', b'user-agent', b'cookie', b'content-length'))
+    _specialHeaders = set(
+        (b'host', b'user-agent', b'cookie', b'content-length'),
+    )
 
     def connectionMade(self):
-        method = getattr(self.factory, 'method', b'GET')
-        self.sendCommand(method, self.factory.path)
+        method = _ensureValidMethod(getattr(self.factory, 'method', b'GET'))
+        self.sendCommand(method, _ensureValidURI(self.factory.path))
         if self.factory.scheme == b'http' and self.factory.port != 80:
             host = self.factory.host + b':' + intToBytes(self.factory.port)
         elif self.factory.scheme == b'https' and self.factory.port != 443:
@@ -362,7 +367,7 @@ class HTTPClientFactory(protocol.ClientFactory):
             # just in case a broken http/1.1 decides to keep connection alive
             self.headers.setdefault(b"connection", b"close")
         self.postdata = postdata
-        self.method = method
+        self.method = _ensureValidMethod(method)
 
         self.setURL(url)
 
@@ -389,6 +394,7 @@ class HTTPClientFactory(protocol.ClientFactory):
         return "<%s: %s>" % (self.__class__.__name__, self.url)
 
     def setURL(self, url):
+        _ensureValidURI(url.strip())
         self.url = url
         uri = URI.fromBytes(url)
         if uri.scheme and uri.host:
@@ -733,7 +739,7 @@ def _makeGetterFactory(url, factoryFactory, contextFactory=None,
 
     @return: The factory created by C{factoryFactory}
     """
-    uri = URI.fromBytes(url)
+    uri = URI.fromBytes(_ensureValidURI(url.strip()))
     factory = factoryFactory(url, *args, **kwargs)
     if uri.scheme == b'https':
         from twisted.internet import ssl
@@ -1493,6 +1499,9 @@ class _AgentBase(object):
         if not isinstance(method, bytes):
             raise TypeError('method={!r} is {}, but must be bytes'.format(
                     method, type(method)))
+
+        method = _ensureValidMethod(method)
+
         # Create minimal headers, if necessary:
         if headers is None:
             headers = Headers()
@@ -1717,6 +1726,7 @@ class Agent(_AgentBase):
 
         @see: L{twisted.web.iweb.IAgent.request}
         """
+        uri = _ensureValidURI(uri.strip())
         parsedURI = URI.fromBytes(uri)
         try:
             endpoint = self._getEndpoint(parsedURI)
@@ -1750,6 +1760,8 @@ class ProxyAgent(_AgentBase):
         """
         Issue a new request via the configured proxy.
         """
+        uri = _ensureValidURI(uri.strip())
+
         # Cache *all* connections under the same key, since we are only
         # connecting to a single destination, the proxy:
         key = ("http-proxy", self._proxyEndpoint)

programming_language: Python
filename: 9647.bugfix
change_type: ModificationType.ADD
diff: @@ -0,0 +1 @@
+All HTTP clients in twisted.web.client now raise a ValueError when called with a method and/or URL that contain invalid characters.  This mitigates CVE-2019-12387.  Thanks to Alex Brasetvik for reporting this vulnerability.
\ No newline at end of file

programming_language: Markdown
filename: injectionhelpers.py
change_type: ModificationType.ADD
diff: @@ -0,0 +1,168 @@
+"""
+Helpers for URI and method injection tests.
+
+@see: U{CVE-2019-12387}
+"""
+
+import string
+
+
+UNPRINTABLE_ASCII = (
+    frozenset(range(0, 128)) -
+    frozenset(bytearray(string.printable, 'ascii'))
+)
+
+NONASCII = frozenset(range(128, 256))
+
+
+
+class MethodInjectionTestsMixin(object):
+    """
+    A mixin that runs HTTP method injection tests.  Define
+    L{MethodInjectionTestsMixin.attemptRequestWithMaliciousMethod} in
+    a L{twisted.trial.unittest.SynchronousTestCase} subclass to test
+    how HTTP client code behaves when presented with malicious HTTP
+    methods.
+
+    @see: U{CVE-2019-12387}
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt to send a request with the given method.  This should
+        synchronously raise a L{ValueError} if either is invalid.
+
+        @param method: the method (e.g. C{GET\x00})
+
+        @param uri: the URI
+
+        @type method:
+        """
+        raise NotImplementedError()
+
+
+    def test_methodWithCLRFRejected(self):
+        """
+        Issuing a request with a method that contains a carriage
+        return and line feed fails with a L{ValueError}.
+        """
+        with self.assertRaises(ValueError) as cm:
+            method = b"GET\r\nX-Injected-Header: value"
+            self.attemptRequestWithMaliciousMethod(method)
+        self.assertRegex(str(cm.exception), "^Invalid method")
+
+
+    def test_methodWithUnprintableASCIIRejected(self):
+        """
+        Issuing a request with a method that contains unprintable
+        ASCII characters fails with a L{ValueError}.
+        """
+        for c in UNPRINTABLE_ASCII:
+            method = b"GET%s" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousMethod(method)
+            self.assertRegex(str(cm.exception), "^Invalid method")
+
+
+    def test_methodWithNonASCIIRejected(self):
+        """
+        Issuing a request with a method that contains non-ASCII
+        characters fails with a L{ValueError}.
+        """
+        for c in NONASCII:
+            method = b"GET%s" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousMethod(method)
+            self.assertRegex(str(cm.exception), "^Invalid method")
+
+
+
+class URIInjectionTestsMixin(object):
+    """
+    A mixin that runs HTTP URI injection tests.  Define
+    L{MethodInjectionTestsMixin.attemptRequestWithMaliciousURI} in a
+    L{twisted.trial.unittest.SynchronousTestCase} subclass to test how
+    HTTP client code behaves when presented with malicious HTTP
+    URIs.
+    """
+
+    def attemptRequestWithMaliciousURI(self, method):
+        """
+        Attempt to send a request with the given URI.  This should
+        synchronously raise a L{ValueError} if either is invalid.
+
+        @param uri: the URI.
+
+        @type method:
+        """
+        raise NotImplementedError()
+
+
+    def test_hostWithCRLFRejected(self):
+        """
+        Issuing a request with a URI whose host contains a carriage
+        return and line feed fails with a L{ValueError}.
+        """
+        with self.assertRaises(ValueError) as cm:
+            uri = b"http://twisted\r\n.invalid/path"
+            self.attemptRequestWithMaliciousURI(uri)
+        self.assertRegex(str(cm.exception), "^Invalid URI")
+
+
+    def test_hostWithWithUnprintableASCIIRejected(self):
+        """
+        Issuing a request with a URI whose host contains unprintable
+        ASCII characters fails with a L{ValueError}.
+        """
+        for c in UNPRINTABLE_ASCII:
+            uri = b"http://twisted%s.invalid/OK" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousURI(uri)
+            self.assertRegex(str(cm.exception), "^Invalid URI")
+
+
+    def test_hostWithNonASCIIRejected(self):
+        """
+        Issuing a request with a URI whose host contains non-ASCII
+        characters fails with a L{ValueError}.
+        """
+        for c in NONASCII:
+            uri = b"http://twisted%s.invalid/OK" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousURI(uri)
+            self.assertRegex(str(cm.exception), "^Invalid URI")
+
+
+    def test_pathWithCRLFRejected(self):
+        """
+        Issuing a request with a URI whose path contains a carriage
+        return and line feed fails with a L{ValueError}.
+        """
+        with self.assertRaises(ValueError) as cm:
+            uri = b"http://twisted.invalid/\r\npath"
+            self.attemptRequestWithMaliciousURI(uri)
+        self.assertRegex(str(cm.exception), "^Invalid URI")
+
+
+    def test_pathWithWithUnprintableASCIIRejected(self):
+        """
+        Issuing a request with a URI whose path contains unprintable
+        ASCII characters fails with a L{ValueError}.
+        """
+        for c in UNPRINTABLE_ASCII:
+            uri = b"http://twisted.invalid/OK%s" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousURI(uri)
+            self.assertRegex(str(cm.exception), "^Invalid URI")
+
+
+    def test_pathWithNonASCIIRejected(self):
+        """
+        Issuing a request with a URI whose path contains non-ASCII
+        characters fails with a L{ValueError}.
+        """
+        for c in NONASCII:
+            uri = b"http://twisted.invalid/OK%s" % (bytearray([c]),)
+            with self.assertRaises(ValueError) as cm:
+                self.attemptRequestWithMaliciousURI(uri)
+            self.assertRegex(str(cm.exception), "^Invalid URI")

programming_language: Python
filename: test_agent.py
change_type: ModificationType.MODIFY
diff: @@ -11,7 +11,7 @@ from io import BytesIO
 
 from zope.interface.verify import verifyObject
 
-from twisted.trial.unittest import TestCase
+from twisted.trial.unittest import TestCase, SynchronousTestCase
 from twisted.web import client, error, http_headers
 from twisted.web._newclient import RequestNotSent, RequestTransmissionFailed
 from twisted.web._newclient import ResponseNeverReceived, ResponseFailed
@@ -51,6 +51,10 @@ from twisted.internet.endpoints import HostnameEndpoint
 from twisted.test.proto_helpers import AccumulatingProtocol
 from twisted.test.iosim import IOPump, FakeTransport
 from twisted.test.test_sslverify import certificatesForAuthorityAndServer
+from twisted.web.test.injectionhelpers import (
+    MethodInjectionTestsMixin,
+    URIInjectionTestsMixin,
+)
 from twisted.web.error import SchemeNotSupported
 from twisted.logger import globalLogPublisher
 
@@ -897,6 +901,7 @@ class AgentTests(TestCase, FakeReactorAndConnectMixin, AgentTestsMixin,
     """
     Tests for the new HTTP client API provided by L{Agent}.
     """
+
     def makeAgent(self):
         """
         @return: a new L{twisted.web.client.Agent} instance
@@ -1327,6 +1332,48 @@ class AgentTests(TestCase, FakeReactorAndConnectMixin, AgentTestsMixin,
 
 
 
+class AgentMethodInjectionTests(
+        FakeReactorAndConnectMixin,
+        MethodInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Agent} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{MethodInjectionTestsMixin}
+        """
+        agent = client.Agent(self.createReactor())
+        uri = b"http://twisted.invalid"
+        agent.request(method, uri, client.Headers(), None)
+
+
+
+class AgentURIInjectionTests(
+        FakeReactorAndConnectMixin,
+        URIInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Agent} against URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided method.
+
+        @param uri: see L{URIInjectionTestsMixin}
+        """
+        agent = client.Agent(self.createReactor())
+        method = b"GET"
+        agent.request(method, uri, client.Headers(), None)
+
+
+
 class AgentHTTPSTests(TestCase, FakeReactorAndConnectMixin,
                       IntegrationTestingMixin):
     """
@@ -3202,3 +3249,101 @@ class HostnameCachingHTTPSPolicyTests(TestCase):
         self.assertEquals(5, len(policy._cache))
 
         self.assertIn(hostn, policy._cache)
+
+
+
+class RequestMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Request} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{MethodInjectionTestsMixin}
+        """
+        client.Request(
+            method=method,
+            uri=b"http://twisted.invalid",
+            headers=http_headers.Headers(),
+            bodyProducer=None,
+        )
+
+
+
+class RequestWriteToMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Request.writeTo} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{MethodInjectionTestsMixin}
+        """
+        headers = http_headers.Headers({b"Host": [b"twisted.invalid"]})
+        req = client.Request(
+            method=b"GET",
+            uri=b"http://twisted.invalid",
+            headers=headers,
+            bodyProducer=None,
+        )
+        req.method = method
+        req.writeTo(StringTransport())
+
+
+
+class RequestURIInjectionTests(
+        URIInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Request} against HTTP URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param method: see L{URIInjectionTestsMixin}
+        """
+        client.Request(
+            method=b"GET",
+            uri=uri,
+            headers=http_headers.Headers(),
+            bodyProducer=None,
+        )
+
+
+
+class RequestWriteToURIInjectionTests(
+        URIInjectionTestsMixin,
+        SynchronousTestCase,
+):
+    """
+    Test L{client.Request.writeTo} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{URIInjectionTestsMixin}
+        """
+        headers = http_headers.Headers({b"Host": [b"twisted.invalid"]})
+        req = client.Request(
+            method=b"GET",
+            uri=b"http://twisted.invalid",
+            headers=headers,
+            bodyProducer=None,
+        )
+        req.uri = uri
+        req.writeTo(StringTransport())

programming_language: Python
filename: test_webclient.py
change_type: ModificationType.MODIFY
diff: @@ -7,6 +7,7 @@ Tests for the old L{twisted.web.client} APIs, C{getPage} and friends.
 
 from __future__ import division, absolute_import
 
+import io
 import os
 from errno import ENOSPC
 
@@ -20,7 +21,8 @@ from twisted.trial import unittest, util
 from twisted.web import server, client, error, resource
 from twisted.web.static import Data
 from twisted.web.util import Redirect
-from twisted.internet import reactor, defer, interfaces
+from twisted.internet import address, reactor, defer, interfaces
+from twisted.internet.protocol import ClientFactory
 from twisted.python.filepath import FilePath
 from twisted.protocols.policies import WrappingFactory
 from twisted.test.proto_helpers import (
@@ -35,6 +37,12 @@ from twisted import test
 from twisted.logger import (globalLogPublisher, FilteringLogObserver,
                             LogLevelFilterPredicate, LogLevel, Logger)
 
+from twisted.web.test.injectionhelpers import (
+    MethodInjectionTestsMixin,
+    URIInjectionTestsMixin,
+)
+
+
 
 serverPEM = FilePath(test.__file__).sibling('server.pem')
 serverPEMPath = serverPEM.asBytesMode().path
@@ -1519,3 +1527,306 @@ class DeprecationTests(unittest.TestCase):
         L{client.HTTPDownloader} is deprecated.
         """
         self._testDeprecatedClass("HTTPDownloader")
+
+
+
+class GetPageMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.getPage} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{MethodInjectionTestsMixin}
+        """
+        uri = b'http://twisted.invalid'
+        client.getPage(uri, method=method)
+
+
+
+class GetPageURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.getPage} against URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: see L{URIInjectionTestsMixin}
+        """
+        client.getPage(uri)
+
+
+
+class DownloadPageMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.getPage} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: see L{MethodInjectionTestsMixin}
+        """
+        uri = b'http://twisted.invalid'
+        client.downloadPage(uri, file=io.BytesIO(), method=method)
+
+
+
+class DownloadPageURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.downloadPage} against URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: see L{URIInjectionTestsMixin}
+        """
+        client.downloadPage(uri, file=io.BytesIO())
+
+
+
+def makeHTTPPageGetterFactory(protocolClass, method, host, path):
+    """
+    Make a L{ClientFactory} that can be used with
+    L{client.HTTPPageGetter} and its subclasses.
+
+    @param protocolClass: The protocol class
+    @type protocolClass: A subclass of L{client.HTTPPageGetter}
+
+    @param method: the HTTP method
+
+    @param host: the host
+
+    @param path: The URI path
+
+    @return: A L{ClientFactory}.
+    """
+    factory = ClientFactory.forProtocol(protocolClass)
+
+    factory.method = method
+    factory.host = host
+    factory.path = path
+
+    factory.scheme = b"http"
+    factory.port = 0
+    factory.headers = {}
+    factory.agent = b"User/Agent"
+    factory.cookies = {}
+
+    return factory
+
+
+
+class HTTPPageGetterMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.HTTPPageGetter} against HTTP method injections.
+    """
+    protocolClass = client.HTTPPageGetter
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: L{MethodInjectionTestsMixin}
+        """
+        transport = StringTransport()
+        factory = makeHTTPPageGetterFactory(
+            self.protocolClass,
+            method=method,
+            host=b"twisted.invalid",
+            path=b"/",
+        )
+        getter = factory.buildProtocol(
+            address.IPv4Address("TCP", "127.0.0.1", 0),
+        )
+        getter.makeConnection(transport)
+
+
+
+class HTTPPageGetterURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Test L{client.HTTPPageGetter} against HTTP URI injections.
+    """
+    protocolClass = client.HTTPPageGetter
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: L{URIInjectionTestsMixin}
+        """
+        transport = StringTransport()
+        # Setting the host and path to the same value is imprecise but
+        # doesn't require parsing an invalid URI.
+        factory = makeHTTPPageGetterFactory(
+            self.protocolClass,
+            method=b"GET",
+            host=uri,
+            path=uri,
+        )
+        getter = factory.buildProtocol(
+            address.IPv4Address("TCP", "127.0.0.1", 0),
+        )
+        getter.makeConnection(transport)
+
+
+
+class HTTPPageDownloaderMethodInjectionTests(
+        HTTPPageGetterMethodInjectionTests
+):
+
+    """
+    Test L{client.HTTPPageDownloader} against HTTP method injections.
+    """
+    protocolClass = client.HTTPPageDownloader
+
+
+
+class HTTPPageDownloaderURIInjectionTests(
+        HTTPPageGetterURIInjectionTests
+):
+    """
+    Test L{client.HTTPPageDownloader} against HTTP URI injections.
+    """
+    protocolClass = client.HTTPPageDownloader
+
+
+
+class HTTPClientFactoryMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPClientFactory} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: L{MethodInjectionTestsMixin}
+        """
+        client.HTTPClientFactory(b"https://twisted.invalid", method)
+
+
+
+class HTTPClientFactoryURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPClientFactory} against HTTP URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: L{URIInjectionTestsMixin}
+        """
+        client.HTTPClientFactory(uri)
+
+
+
+class HTTPClientFactorySetURLURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPClientFactory.setURL} against HTTP URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: L{URIInjectionTestsMixin}
+        """
+        client.HTTPClientFactory(b"https://twisted.invalid").setURL(uri)
+
+
+
+class HTTPDownloaderMethodInjectionTests(
+        MethodInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPDownloader} against HTTP method injections.
+    """
+
+    def attemptRequestWithMaliciousMethod(self, method):
+        """
+        Attempt a request with the provided method.
+
+        @param method: L{MethodInjectionTestsMixin}
+        """
+        client.HTTPDownloader(
+            b"https://twisted.invalid",
+            io.BytesIO(),
+            method=method,
+        )
+
+
+
+class HTTPDownloaderURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPDownloader} against HTTP URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: L{URIInjectionTestsMixin}
+        """
+        client.HTTPDownloader(uri, io.BytesIO())
+
+
+
+class HTTPDownloaderSetURLURIInjectionTests(
+        URIInjectionTestsMixin,
+        unittest.SynchronousTestCase,
+):
+    """
+    Tests L{client.HTTPDownloader.setURL} against HTTP URI injections.
+    """
+
+    def attemptRequestWithMaliciousURI(self, uri):
+        """
+        Attempt a request with the provided URI.
+
+        @param uri: L{URIInjectionTestsMixin}
+        """
+        downloader = client.HTTPDownloader(
+            b"https://twisted.invalid",
+            io.BytesIO(),
+        )
+        downloader.setURL(uri)

programming_language: Python