Gateway node provides connectivity to the nodes inside MANET. Based upon the route to gateway node found during discovery phase; source node relies on intermediate nodes to forward packets to the gateway node. We have identified a vulnerability of the gateway discovery phase where adversaries can forcibly introduce routes having wormholes exploiting the routing race conditions. We have termed such routes having wormholes as the pseudo routes. The pseudo route attack is a more generalized form of the wormhole attack where wormhole start and end points can be any two nodes in the route and even multiple wormholes can be present in the same route. We have proposed an end-to-end approach using localization information to detect and prevent pseudo route attacks. Simulation results are presented to show the impact of pseudo route attack under various scenarios as well as for performance of the proposed protocol. We found that attack impact is more when the gateway is at the corner of the network.