Be stricter about JSON that is accepted by Synapse (#8106)

1 files changed, 2 insertions, 3 deletions

diff --git a/synapse/http/federation/well_known_resolver.py b/synapse/http/federation/well_known_resolver.py
index 89a3b041ce..f794315deb 100644
--- a/synapse/http/federation/well_known_resolver.py
+++ b/synapse/http/federation/well_known_resolver.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
 import logging
 import random
 import time
@@ -26,7 +25,7 @@ from twisted.web.http import stringToDatetime
 from twisted.web.http_headers import Headers
 
 from synapse.logging.context import make_deferred_yieldable
-from synapse.util import Clock
+from synapse.util import Clock, json_decoder
 from synapse.util.caches.ttlcache import TTLCache
 from synapse.util.metrics import Measure
 
@@ -181,7 +180,7 @@ class WellKnownResolver(object):
             if response.code != 200:
                 raise Exception("Non-200 response %s" % (response.code,))
 
-            parsed_body = json.loads(body.decode("utf-8"))
+            parsed_body = json_decoder.decode(body.decode("utf-8"))
             logger.info("Response from .well-known: %s", parsed_body)
 
             result = parsed_body["m.server"].encode("ascii")