A denial of service issue exists in the `LoginPacket` handler. Remote attackers can inject numerous junk properties into the `clientData` JWT (JSON Web Token), which is a compact, URL-safe means of representing claims to be transferred between two parties. This occurs because the `JsonMapper` instance used to process the JWT body is configured to warn about unexpected properties rather than rejecting them. By crafting malicious login packets with excessive unknown properties, an attacker can cause the server to flood warning messages and waste CPU time, leading to degraded performance.