JDK 6u19 provides a new system property, called sun.security.ssl.allowUnsafeRenegotiation, that enables TLS/SSL renegotiation. For more information, see http://java.sun.com/javase/javaseforbusiness/docs/TLSReadme.html. Setting this property to true in GlassFish Server GlassFish enables the renegotiation. However, it also makes GlassFish Server once again vulnerable to MITM attack.