Java Runtime Environment (JRE) for Sun JDK and JRE 6 Update 10 and earlier; JDK and JRE 5.0 Update 16 and earlier; SDK and JRE 1.4.2_18 and earlier; and SDK and JRE 1.3.1_23 and earlier creates temporary files with predictable file names, which allows attackers to write malicious JAR files via unknown vectors.