From 2b9692621b0ee27def37c597621ea6a20c757ca8 Mon Sep 17 00:00:00 2001
From: Florence Blanc-Renaud <flo@redhat.com>
Date: Tue, 21 Nov 2023 09:37:25 +0100
Subject: [PATCH] Check the HTTP Referer header on all requests
The referer was only checked in WSGIExecutioner classes:
- jsonserver
- KerberosWSGIExecutioner
- xmlserver
- jsonserver_kerb
This left /i18n_messages, /session/login_kerberos,
/session/login_x509, /session/login_password,
/session/change_password and /session/sync_token unprotected
against CSRF attacks.
CVE-2023-5455
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
---
ipaserver/rpcserver.py | 34 +++++++++++++++++++++++++++++++---
1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/ipaserver/rpcserver.py b/ipaserver/rpcserver.py
index 3c831a55888ba723fc52c988593c364fb7883b7b..91bec2133479a9b4bd1311e6be800d982cf855f3 100644
--- a/ipaserver/rpcserver.py
+++ b/ipaserver/rpcserver.py
@@ -136,6 +136,19 @@ _success_template = """<html>
</html>"""
class HTTP_Status(plugable.Plugin):
+ def check_referer(self, environ):
+ if "HTTP_REFERER" not in environ:
+ logger.error("Rejecting request with missing Referer")
+ return False
+ if (not environ["HTTP_REFERER"].startswith(
+ "https://%s/ipa" % self.api.env.host)
+ and not self.env.in_tree):
+ logger.error("Rejecting request with bad Referer %s",
+ environ["HTTP_REFERER"])
+ return False
+ logger.debug("Valid Referer %s", environ["HTTP_REFERER"])
+ return True
+
def not_found(self, environ, start_response, url, message):
"""
Return a 404 Not Found error.
@@ -297,9 +310,6 @@ class wsgi_dispatch(Executioner, HTTP_Status):
self.__apps[key] = app
-
-
-
class WSGIExecutioner(Executioner):
"""
Base class for execution backends with a WSGI application interface.
@@ -803,6 +813,9 @@ class jsonserver_session(jsonserver, KerberosSession):
logger.debug('WSGI jsonserver_session.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
# Redirect to login if no Kerberos credentials
ccache_name = self.get_environ_creds(environ)
if ccache_name is None:
@@ -843,6 +856,9 @@ class KerberosLogin(Backend, KerberosSession):
def __call__(self, environ, start_response):
logger.debug('WSGI KerberosLogin.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
# Redirect to login if no Kerberos credentials
user_ccache_name = self.get_environ_creds(environ)
if user_ccache_name is None:
@@ -861,6 +877,9 @@ class login_x509(KerberosLogin):
def __call__(self, environ, start_response):
logger.debug('WSGI login_x509.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
if 'KRB5CCNAME' not in environ:
return self.unauthorized(
environ, start_response, 'KRB5CCNAME not set',
@@ -881,6 +900,9 @@ class login_password(Backend, KerberosSession):
def __call__(self, environ, start_response):
logger.debug('WSGI login_password.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
# Get the user and password parameters from the request
content_type = environ.get('CONTENT_TYPE', '').lower()
if not content_type.startswith('application/x-www-form-urlencoded'):
@@ -1018,6 +1040,9 @@ class change_password(Backend, HTTP_Status):
def __call__(self, environ, start_response):
logger.info('WSGI change_password.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
# Get the user and password parameters from the request
content_type = environ.get('CONTENT_TYPE', '').lower()
if not content_type.startswith('application/x-www-form-urlencoded'):
@@ -1231,6 +1256,9 @@ class xmlserver_session(xmlserver, KerberosSession):
logger.debug('WSGI xmlserver_session.__call__:')
+ if not self.check_referer(environ):
+ return self.bad_request(environ, start_response, 'denied')
+
ccache_name = environ.get('KRB5CCNAME')
# Redirect to /ipa/xml if no Kerberos credentials
--
2.26.3