Stack-based buffer overflow in 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 allows locally-launched and possibly remote untrusted Java applications to execute arbitrary code via a JAR file with a long Main-Class manifest entry.