Fixed a security issue related to password resets

Full disclosure and new release are forthcoming

backport from master

django/contrib/auth/tests/urls.py

@@ -19,6 +19,7 @@ urlpatterns = urlpatterns + patterns('',
     (r'^logout/next_page/$', 'django.contrib.auth.views.logout', dict(next_page='/somewhere/')),
     (r'^remote_user/$', remote_user_auth_view),
     (r'^password_reset_from_email/$', 'django.contrib.auth.views.password_reset', dict(from_email='staffmember@example.com')),
+    (r'^admin_password_reset/$', 'django.contrib.auth.views.password_reset', dict(is_admin_site=True)),
     (r'^login_required/$', login_required(password_reset)),
     (r'^login_required_login_url/$', login_required(password_reset, login_url='/somewhere/')),
 )

django/contrib/auth/tests/views.py

@@ -9,6 +9,7 @@ from django.contrib.sites.models import Site, RequestSite
 from django.contrib.auth.models import User
 from django.test import TestCase
 from django.core import mail
+from django.core.exceptions import SuspiciousOperation
 from django.core.urlresolvers import reverse
 from django.http import QueryDict
 
@@ -69,6 +70,44 @@ class PasswordResetTest(AuthViewsTestCase):
         self.assertEqual(len(mail.outbox), 1)
         self.assertEqual("staffmember@example.com", mail.outbox[0].from_email)
 
+    def test_admin_reset(self):
+        "If the reset view is marked as being for admin, the HTTP_HOST header is used for a domain override."
+        response = self.client.post('/admin_password_reset/',
+            {'email': 'staffmember@example.com'},
+            HTTP_HOST='adminsite.com'
+        )
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(len(mail.outbox), 1)
+        self.assertTrue("http://adminsite.com" in mail.outbox[0].body)
+        self.assertEqual(settings.DEFAULT_FROM_EMAIL, mail.outbox[0].from_email)
+
+    def test_poisoned_http_host(self):
+        "Poisoned HTTP_HOST headers can't be used for reset emails"
+        # This attack is based on the way browsers handle URLs. The colon
+        # should be used to separate the port, but if the URL contains an @,
+        # the colon is interpreted as part of a username for login purposes,
+        # making 'evil.com' the request domain. Since HTTP_HOST is used to
+        # produce a meaningful reset URL, we need to be certain that the
+        # HTTP_HOST header isn't poisoned. This is done as a check when get_host()
+        # is invoked, but we check here as a practical consequence.
+        def test_host_poisoning():
+            self.client.post('/password_reset/',
+                {'email': 'staffmember@example.com'},
+                HTTP_HOST='www.example:dr.frankenstein@evil.tld'
+            )
+        self.assertRaises(SuspiciousOperation, test_host_poisoning)
+        self.assertEqual(len(mail.outbox), 0)
+
+    def test_poisoned_http_host_admin_site(self):
+        "Poisoned HTTP_HOST headers can't be used for reset emails on admin views"
+        def test_host_poisoning():
+            self.client.post('/admin_password_reset/',
+                {'email': 'staffmember@example.com'},
+                HTTP_HOST='www.example:dr.frankenstein@evil.tld'
+            )
+        self.assertRaises(SuspiciousOperation, test_host_poisoning)
+        self.assertEqual(len(mail.outbox), 0)
+
     def _test_confirm_start(self):
         # Start by creating the email
         response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})

django/contrib/auth/views.py

@@ -151,7 +151,7 @@ def password_reset(request, is_admin_site=False,
                 'request': request,
             }
             if is_admin_site:
-                opts = dict(opts, domain_override=request.META['HTTP_HOST'])
+                opts = dict(opts, domain_override=request.get_host())
             form.save(**opts)
             return HttpResponseRedirect(post_reset_redirect)
     else:

django/http/__init__.py

@@ -165,6 +165,11 @@ class HttpRequest(object):
             server_port = str(self.META['SERVER_PORT'])
             if server_port != (self.is_secure() and '443' or '80'):
                 host = '%s:%s' % (host, server_port)
+
+        # Disallow potentially poisoned hostnames.
+        if set(';/?@&=+$,').intersection(host):
+            raise SuspiciousOperation('Invalid HTTP_HOST header: %s' % host)
+
         return host
 
     def get_full_path(self):