Merge tag 'v1.15.2'

Synapse 1.15.2 (2020-07-02)
===========================

Due to the two security issues highlighted below, server administrators are
encouraged to update Synapse. We are not aware of these vulnerabilities being
exploited in the wild.

Security advisory
-----------------

* A malicious homeserver could force Synapse to reset the state in a room to a
  small subset of the correct state. This affects all Synapse deployments which
  federate with untrusted servers. ([96e9afe6](https://github.com/matrix-org/synapse/commit/96e9afe62500310977dc3cbc99a8d16d3d2fa15c))
* HTML pages served via Synapse were vulnerable to clickjacking attacks. This
  predominantly affects homeservers with single-sign-on enabled, but all server
  administrators are encouraged to upgrade. ([ea26e9a9](https://github.com/matrix-org/synapse/commit/ea26e9a98b0541fc886a1cb826a38352b7599dbe))

  This was reported by [Quentin Gliech](https://sandhose.fr/).

1 files changed, 4 insertions, 6 deletions

diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index b9ffe86b2a..c8d2de7b54 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -38,7 +38,7 @@ from synapse.config.ratelimiting import FederationRateLimitConfig
 from synapse.config.registration import RegistrationConfig
 from synapse.config.server import is_threepid_reserved
 from synapse.handlers.auth import AuthHandler
-from synapse.http.server import finish_request
+from synapse.http.server import finish_request, respond_with_html
 from synapse.http.servlet import (
     RestServlet,
     assert_params_in_dict,
@@ -306,17 +306,15 @@ class RegistrationSubmitTokenServlet(RestServlet):
 
             # Otherwise show the success template
             html = self.config.email_registration_template_success_html_content
-
-            request.setResponseCode(200)
+            status_code = 200
         except ThreepidValidationError as e:
-            request.setResponseCode(e.code)
+            status_code = e.code
 
             # Show a failure page with a reason
             template_vars = {"failure_reason": e.msg}
             html = self.failure_email_template.render(**template_vars)
 
-        request.write(html.encode("utf-8"))
-        finish_request(request)
+        respond_with_html(request, status_code, html)
 
 
 class UsernameAvailabilityRestServlet(RestServlet):