From 37cdc407993d3c9aff84bdc84616f0bbc3974552 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=CE=B6eh=20Matt?= <5415177+ZehMatt@users.noreply.github.com>
Date: Sat, 11 Nov 2023 18:59:46 +0200
Subject: [PATCH] Fix #20964: Crash when invalid network group id is used

---
 src/openrct2/network/NetworkBase.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/openrct2/network/NetworkBase.cpp b/src/openrct2/network/NetworkBase.cpp
index 2567717efe..46cbcc42ab 100644
--- a/src/openrct2/network/NetworkBase.cpp
+++ b/src/openrct2/network/NetworkBase.cpp
@@ -2643,7 +2643,10 @@ void NetworkBase::ServerHandleAuth(NetworkConnection& connection, NetworkPacket&
         if (connection.AuthStatus == NetworkAuth::Verified)
         {
             const NetworkGroup* group = GetGroupByID(GetGroupIDByHash(connection.Key.PublicKeyHash()));
-            passwordless = group->CanPerformAction(NetworkPermission::PasswordlessLogin);
+            if (group != nullptr)
+            {
+                passwordless = group->CanPerformAction(NetworkPermission::PasswordlessLogin);
+            }
         }
         if (gameversion != NetworkGetVersion())
         {
@@ -3649,6 +3652,11 @@ GameActions::Result NetworkModifyGroups(
         case ModifyGroupType::SetName:
         {
             NetworkGroup* group = network.GetGroupByID(groupId);
+            if (group == nullptr)
+            {
+                return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_RENAME_GROUP, STR_NONE);
+            }
+
             const char* oldName = group->GetName().c_str();
 
             if (strcmp(oldName, name.c_str()) == 0)