Fix a long-standing spec compliance bug where Synapse would accept a trailing slash on the end of `/get_missing_events` federation requests. (#13789)

* Don't accept a trailing slash on the end of /get_missing_events

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/changelog.d/13789.bugfix b/changelog.d/13789.bugfix
new file mode 100644

index 0000000000..9e1e3e0fa7
--- /dev/null
+++ b/changelog.d/13789.bugfix
@@ -0,0 +1 @@
+Fix a long-standing spec compliance bug where Synapse would accept a trailing slash on the end of `/get_missing_events` federation requests.
\ No newline at end of file
diff --git a/synapse/federation/transport/server/federation.py b/synapse/federation/transport/server/federation.py

index f7884bfbe0..6bb4659c4c 100644
--- a/synapse/federation/transport/server/federation.py
+++ b/synapse/federation/transport/server/federation.py
@@ -549,8 +549,7 @@ class FederationClientKeysClaimServlet(BaseFederationServerServlet):
 
 
 class FederationGetMissingEventsServlet(BaseFederationServerServlet):
-    # TODO(paul): Why does this path alone end with "/?" optional?
-    PATH = "/get_missing_events/(?P<room_id>[^/]*)/?"
+    PATH = "/get_missing_events/(?P<room_id>[^/]*)"
 
     async def on_POST(
         self,