The Java Runtime Environment (JRE) for Sun JDK and JRE 6 Update 10 and earlier; JDK and JRE 5.0 Update 16 and earlier; and SDK and JRE 1.4.2_18 and earlier does not properly enforce context of ZoneInfo objects during deserialization, which allows remote attackers to run untrusted applets and applications in a privileged context, as demonstrated by "deserializing Calendar objects".