From 9827ad43e4338c40f51699705b5ff74bd12aba2c Mon Sep 17 00:00:00 2001
From: Badlop <badlop@process-one.net>
Date: Wed, 15 Jan 2025 20:15:40 +0100
Subject: [PATCH] mod_muc_admin: Verify room option value before setting it
 (#4337)

---
 src/mod_muc_admin.erl | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/mod_muc_admin.erl b/src/mod_muc_admin.erl
index f9592d539..36d37b899 100644
--- a/src/mod_muc_admin.erl
+++ b/src/mod_muc_admin.erl
@@ -1722,9 +1722,8 @@ format_room_option(OptionString, ValueString) ->
 		password -> ValueString;
 		subject ->ValueString;
 		subject_author ->ValueString;
-		presence_broadcast ->misc:expr_to_term(ValueString);
-		max_users -> binary_to_integer(ValueString);
-		voice_request_min_interval -> binary_to_integer(ValueString);
+		max_users -> try_convert_integer(Option, ValueString);
+		voice_request_min_interval -> try_convert_integer(Option, ValueString);
 		vcard -> ValueString;
 		vcard_xupdate when ValueString /= <<"undefined">>,
 				   ValueString /= <<"external">> ->
@@ -1735,10 +1734,35 @@ format_room_option(OptionString, ValueString) ->
 		    [parse_affiliation_string(Opt) || Opt <- str:tokens(ValueString, <<",">>)];
 		subscribers ->
 		    [parse_subscription_string(Opt) || Opt <- str:tokens(ValueString, <<",">>)];
-		_ -> misc:binary_to_atom(ValueString)
+                allow_private_messages_from_visitors when
+                      (ValueString == <<"anyone">>) or
+                      (ValueString == <<"moderators">>) or
+                      (ValueString == <<"nobody">>) -> binary_to_existing_atom(ValueString);
+                allowpm when
+                      (ValueString == <<"anyone">>) or
+                      (ValueString == <<"participants">>) or
+                      (ValueString == <<"moderators">>) or
+                      (ValueString == <<"none">>) -> binary_to_existing_atom(ValueString);
+		presence_broadcast when
+                      (ValueString == <<"participant">>) or
+                      (ValueString == <<"moderator">>) or
+                      (ValueString == <<"visitor">>) -> binary_to_existing_atom(ValueString);
+		_ when ValueString == <<"true">> -> true;
+		_ when ValueString == <<"false">> -> false;
+                _ -> throw_error(Option, ValueString)
 	    end,
     {Option, Value}.
 
+try_convert_integer(Option, ValueString) ->
+    try binary_to_integer(ValueString) of
+	I when is_integer(I) -> I
+    catch _:badarg ->
+        throw_error(Option, ValueString)
+    end.
+
+throw_error(O, V) ->
+    throw({error, "Invalid value for that option", O, V}).
+
 parse_affiliation_string(String) ->
     {Type, JidS} = case String of
 		       <<"owner:", Jid/binary>> -> {owner, Jid};