Fix a security issue in the auth system. Disclosure and new release forthcoming.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15032 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/auth/tests/tokens.py

@@ -72,3 +72,14 @@ class TokenGeneratorTest(TestCase):
         p0 = PasswordResetTokenGenerator()
         tk1 = _make_token(user)
         self.assertTrue(p0.check_token(user, tk1))
+
+    def test_date_length(self):
+        """
+        Make sure we don't allow overly long dates, causing a potential DoS.
+        """
+        user = User.objects.create_user('ima1337h4x0r', 'test4@example.com', 'p4ssw0rd')
+        p0 = PasswordResetTokenGenerator()
+
+        # This will put a 14-digit base36 timestamp into the token, which is too large.
+        tk1 = p0._make_token_with_timestamp(user, 175455491841851871349)
+        self.assertFalse(p0.check_token(user, tk1))

django/contrib/auth/urls.py

@@ -11,7 +11,7 @@ urlpatterns = patterns('',
     (r'^password_change/done/$', 'django.contrib.auth.views.password_change_done'),
     (r'^password_reset/$', 'django.contrib.auth.views.password_reset'),
     (r'^password_reset/done/$', 'django.contrib.auth.views.password_reset_done'),
-    (r'^reset/(?P<uidb36>[0-9A-Za-z]+)-(?P<token>.+)/$', 'django.contrib.auth.views.password_reset_confirm'),
+    (r'^reset/(?P<uidb36>[0-9A-Za-z]{1,13})-(?P<token>[0-9A-Za-z]{1,13}-[0-9A-Za-z]{1,20})/$', 'django.contrib.auth.views.password_reset_confirm'),
     (r'^reset/done/$', 'django.contrib.auth.views.password_reset_complete'),
 )
 

django/utils/http.py

@@ -73,8 +73,13 @@ def http_date(epoch_seconds=None):
 
 def base36_to_int(s):
     """
-    Convertd a base 36 string to an integer
+    Converts a base 36 string to an ``int``. To prevent
+    overconsumption of server resources, raises ``ValueError` if the
+    input is longer than 13 base36 digits (13 digits is sufficient to
+    base36-encode any 64-bit integer).
     """
+    if len(s) > 13:
+        raise ValueError("Base36 input too large")
     return int(s, 36)
 
 def int_to_base36(i):