diff --git a/django/utils/http.py b/django/utils/http.py index 2dce7d3add..6e782bd576 100644 --- a/django/utils/http.py +++ b/django/utils/http.py @@ -290,8 +290,12 @@ def is_safe_url(url, host=None): url = url.strip() if not url: return False - # Chrome treats \ completely as / - url = url.replace('\\', '/') + # Chrome treats \ completely as / in paths but it could be part of some + # basic auth credentials so we need to check both URLs. + return _is_safe_url(url, host) and _is_safe_url(url.replace('\\', '/'), host) + + +def _is_safe_url(url, host): # Chrome considers any URL with more than two slashes to be absolute, but # urlparse is not so flexible. Treat any url with three slashes as unsafe. if url.startswith('///'): diff --git a/docs/releases/1.8.10.txt b/docs/releases/1.8.10.txt index d93f243720..73c7cc04a4 100644 --- a/docs/releases/1.8.10.txt +++ b/docs/releases/1.8.10.txt @@ -6,6 +6,22 @@ Django 1.8.10 release notes Django 1.8.10 fixes two security issues and several bugs in 1.8.9. +CVE-2016-2512: Malicious redirect and possible XSS attack via user-supplied redirect URLs containing basic auth +=============================================================================================================== + +Django relies on user input in some cases (e.g. +:func:`django.contrib.auth.views.login` and :doc:`i18n `) +to redirect the user to an "on success" URL. The security check for these +redirects (namely ``django.utils.http.is_safe_url()``) considered some URLs +with basic authentication credentials "safe" when they shouldn't be. + +For example, a URL like ``http://mysite.example.com\@attacker.com`` would be +considered safe if the request's host is ``http://mysite.example.com``, but +redirecting to this URL sends the user to ``attacker.com``. + +Also, if a developer relies on ``is_safe_url()`` to provide safe redirect +targets and puts such a URL into a link, they could suffer from an XSS attack. + Bugfixes ======== diff --git a/docs/releases/1.9.3.txt b/docs/releases/1.9.3.txt index 8cc57d8a81..056122b16e 100644 --- a/docs/releases/1.9.3.txt +++ b/docs/releases/1.9.3.txt @@ -6,6 +6,22 @@ Django 1.9.3 release notes Django 1.9.3 fixes two security issues and several bugs in 1.9.2. +CVE-2016-2512: Malicious redirect and possible XSS attack via user-supplied redirect URLs containing basic auth +=============================================================================================================== + +Django relies on user input in some cases (e.g. +:func:`django.contrib.auth.views.login` and :doc:`i18n `) +to redirect the user to an "on success" URL. The security check for these +redirects (namely ``django.utils.http.is_safe_url()``) considered some URLs +with basic authentication credentials "safe" when they shouldn't be. + +For example, a URL like ``http://mysite.example.com\@attacker.com`` would be +considered safe if the request's host is ``http://mysite.example.com``, but +redirecting to this URL sends the user to ``attacker.com``. + +Also, if a developer relies on ``is_safe_url()`` to provide safe redirect +targets and puts such a URL into a link, they could suffer from an XSS attack. + Bugfixes ======== diff --git a/tests/utils_tests/test_http.py b/tests/utils_tests/test_http.py index 6234e269ab..2a9b553b6a 100644 --- a/tests/utils_tests/test_http.py +++ b/tests/utils_tests/test_http.py @@ -97,6 +97,11 @@ class TestUtilsHttp(unittest.TestCase): 'javascript:alert("XSS")', '\njavascript:alert(x)', '\x08//example.com', + r'http://otherserver\@example.com', + r'http:\\testserver\@example.com', + r'http://testserver\me:pass@example.com', + r'http://testserver\@example.com', + r'http:\\testserver\confirm\me@example.com', '\n'): self.assertFalse(http.is_safe_url(bad_url, host='testserver'), "%s should be blocked" % bad_url) for good_url in ('/view/?param=http://example.com', @@ -106,8 +111,15 @@ class TestUtilsHttp(unittest.TestCase): 'https://testserver/', 'HTTPS://testserver/', '//testserver/', + 'http://testserver/confirm?email=me@example.com', '/url%20with%20spaces/'): self.assertTrue(http.is_safe_url(good_url, host='testserver'), "%s should be allowed" % good_url) + # Valid basic auth credentials are allowed. + self.assertTrue(http.is_safe_url(r'http://user:pass@testserver/', host='user:pass@testserver')) + # A path without host is allowed. + self.assertTrue(http.is_safe_url('/confirm/me@example.com')) + # Basic auth without host is not allowed. + self.assertFalse(http.is_safe_url(r'http://testserver\@example.com')) def test_urlsafe_base64_roundtrip(self): bytestring = b'foo'