Core/Gossip: Add security to C++ scripted gossip options by checking guid of the object that the player is interecting with. Idea by @LilleCarl

Closes #11567

3 files changed, 24 insertions, 5 deletions

diff --git a/src/server/game/Entities/Creature/GossipDef.cpp b/src/server/game/Entities/Creature/GossipDef.cpp
index ffb28849925..8671caf864d 100644
--- a/src/server/game/Entities/Creature/GossipDef.cpp
+++ b/src/server/game/Entities/Creature/GossipDef.cpp
@@ -28,6 +28,7 @@ GossipMenu::GossipMenu()
 {
     _menuId = 0;
     _locale = DEFAULT_LOCALE;
+    _senderGUID = 0;
 }
 
 GossipMenu::~GossipMenu()
@@ -166,8 +167,10 @@ void PlayerMenu::ClearMenus()
     _questMenu.ClearMenu();
 }
 
-void PlayerMenu::SendGossipMenu(uint32 titleTextId, uint64 objectGUID) const
+void PlayerMenu::SendGossipMenu(uint32 titleTextId, uint64 objectGUID)
 {
+    _gossipMenu.SetSenderGUID(objectGUID);
+
     WorldPacket data(SMSG_GOSSIP_MESSAGE, 100);         // guess size
     data << uint64(objectGUID);
     data << uint32(_gossipMenu.GetMenuId());            // new 2.4.0
@@ -222,8 +225,10 @@ void PlayerMenu::SendGossipMenu(uint32 titleTextId, uint64 objectGUID) const
     _session->SendPacket(&data);
 }
 
-void PlayerMenu::SendCloseGossip() const
+void PlayerMenu::SendCloseGossip()
 {
+    _gossipMenu.SetSenderGUID(0);
+
     WorldPacket data(SMSG_GOSSIP_COMPLETE, 0);
     _session->SendPacket(&data);
 }
diff --git a/src/server/game/Entities/Creature/GossipDef.h b/src/server/game/Entities/Creature/GossipDef.h
index d9ec3619cd8..e8fac878409 100644
--- a/src/server/game/Entities/Creature/GossipDef.h
+++ b/src/server/game/Entities/Creature/GossipDef.h
@@ -167,6 +167,8 @@ class GossipMenu
 
         void SetMenuId(uint32 menu_id) { _menuId = menu_id; }
         uint32 GetMenuId() const { return _menuId; }
+        void SetSenderGUID(uint64 guid) { _senderGUID = guid; }
+        uint64 GetSenderGUID() const { return _senderGUID; }
         void SetLocale(LocaleConstant locale) { _locale = locale; }
         LocaleConstant GetLocale() const { return _locale; }
 
@@ -215,6 +217,7 @@ class GossipMenu
         GossipMenuItemContainer _menuItems;
         GossipMenuItemDataContainer _menuItemData;
         uint32 _menuId;
+        uint64 _senderGUID;
         LocaleConstant _locale;
 };
 
@@ -264,8 +267,8 @@ class PlayerMenu
         uint32 GetGossipOptionAction(uint32 selection) const { return _gossipMenu.GetMenuItemAction(selection); }
         bool IsGossipOptionCoded(uint32 selection) const { return _gossipMenu.IsMenuItemCoded(selection); }
 
-        void SendGossipMenu(uint32 titleTextId, uint64 objectGUID) const;
-        void SendCloseGossip() const;
+        void SendGossipMenu(uint32 titleTextId, uint64 objectGUID);
+        void SendCloseGossip();
         void SendPointOfInterest(uint32 poiId) const;
 
         /*********************************************************/
diff --git a/src/server/game/Handlers/MiscHandler.cpp b/src/server/game/Handlers/MiscHandler.cpp
index 60f4fb09c28..d181c64f199 100644
--- a/src/server/game/Handlers/MiscHandler.cpp
+++ b/src/server/game/Handlers/MiscHandler.cpp
@@ -97,9 +97,19 @@ void WorldSession::HandleGossipSelectOptionOpcode(WorldPacket& recvData)
 
     recvData >> guid >> menuId >> gossipListId;
 
+    if (!_player->PlayerTalkClass->GetGossipMenu().GetItem(gossipListId))
+    {
+        recvData.rfinish();
+        return;
+    }
+
     if (_player->PlayerTalkClass->IsGossipOptionCoded(gossipListId))
         recvData >> code;
 
+    // Prevent cheating on C++ scripted menus
+    if (_player->PlayerTalkClass->GetGossipMenu().GetSenderGUID() != guid)
+        return;
+
     Creature* unit = NULL;
     GameObject* go = NULL;
     if (IS_CRE_OR_VEH_GUID(guid))
@@ -151,7 +161,8 @@ void WorldSession::HandleGossipSelectOptionOpcode(WorldPacket& recvData)
         else
         {
             go->AI()->GossipSelectCode(_player, menuId, gossipListId, code.c_str());
-            sScriptMgr->OnGossipSelectCode(_player, go, _player->PlayerTalkClass->GetGossipOptionSender(gossipListId), _player->PlayerTalkClass->GetGossipOptionAction(gossipListId), code.c_str());
+            if (!sScriptMgr->OnGossipSelectCode(_player, go, _player->PlayerTalkClass->GetGossipOptionSender(gossipListId), _player->PlayerTalkClass->GetGossipOptionAction(gossipListId), code.c_str()))
+                _player->OnGossipSelect(unit, gossipListId, menuId);
         }
     }
     else