[Server] Fix unauthenticated crash via replay submit code (#7072)

cmdReplaySubmitCode dereferenced userInfo without an authentication
guard, allowing an unauthenticated connection with a valid replay code
to segfault the server. Add the same authState != PasswordRight guard
used by all other replay handlers, and gate session command dispatch on
a pre-auth whitelist so future handlers cannot be reached before login.

Took 2 minutes

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

libcockatrice_network/libcockatrice/network/server/remote/server_protocolhandler.cpp

@@ -133,6 +133,22 @@ void Server_ProtocolHandler::sendProtocolItem(const RoomEvent &item)
 Response::ResponseCode Server_ProtocolHandler::processSessionCommandContainer(const CommandContainer &cont,
                                                                               ResponseContainer &rc)
 {
+    const auto isPreAuthSessionCommand = [](SessionCommand::SessionCommandType type) {
+        switch (type) {
+            case SessionCommand::PING:
+            case SessionCommand::LOGIN:
+            case SessionCommand::REGISTER:
+            case SessionCommand::ACTIVATE:
+            case SessionCommand::FORGOT_PASSWORD_REQUEST:
+            case SessionCommand::FORGOT_PASSWORD_RESET:
+            case SessionCommand::FORGOT_PASSWORD_CHALLENGE:
+            case SessionCommand::REQUEST_PASSWORD_SALT:
+                return true;
+            default:
+                return false;
+        }
+    };
+
     Response::ResponseCode finalResponseCode = Response::RespOk;
     for (int i = cont.session_command_size() - 1; i >= 0; --i) {
         Response::ResponseCode resp = Response::RespInvalidCommand;
@@ -141,7 +157,11 @@ Response::ResponseCode Server_ProtocolHandler::processSessionCommandContainer(co
         if (num != SessionCommand::PING) { // don't log ping commands
             logDebugMessage(getSafeDebugString(sc));
         }
-        switch ((SessionCommand::SessionCommandType)num) {
+        const auto commandType = static_cast<SessionCommand::SessionCommandType>(num);
+        if (authState == NotLoggedIn && !isPreAuthSessionCommand(commandType)) {
+            resp = Response::RespLoginNeeded;
+        } else {
+            switch (commandType) {
                 case SessionCommand::PING:
                     resp = cmdPing(sc.GetExtension(Command_Ping::ext), rc);
                     break;
@@ -169,6 +189,7 @@ Response::ResponseCode Server_ProtocolHandler::processSessionCommandContainer(co
                 default:
                     resp = processExtendedSessionCommand(num, sc, rc);
             }
+        }
         if (resp != Response::RespOk) {
             finalResponseCode = resp;
         }

servatrice/src/serversocketinterface.cpp

@@ -896,6 +896,10 @@ Response::ResponseCode AbstractServerSocketInterface::cmdReplayGetCode(const Com
 Response::ResponseCode AbstractServerSocketInterface::cmdReplaySubmitCode(const Command_ReplaySubmitCode &cmd,
                                                                           ResponseContainer & /*rc*/)
 {
+    if (authState != PasswordRight) {
+        return Response::RespFunctionNotAllowed;
+    }
+
     // code is of the form <game-id>-<hash>
     QString code = QString::fromStdString(cmd.replay_code());
     QStringList split = code.split("-");