Unspecified vulnerability in the Java Runtime Environment (JRE) Applet Class Loader in Sun JDK and JRE 5.0 Update 11 and earlier, 6 through 6 Update 1, and SDK and JRE 1.4.2_14 and earlier, allows remote attackers to violate the security model for an applet's outbound connections by connecting to certain localhost services running on the machine that loaded the applet.