CVE 2009-2675

Integer overflow in the unpack200 utility in Sun Java Runtime Environment (JRE) in JDK and JRE 6 before Update 15, and JDK and JRE 5.0 before Update 20, allows context-dependent attackers to gain privileges via unspecified length fields in the header of a Pack200-compressed JAR file, which leads to a heap-based buffer overflow during decompression.

See the CVE page on Mitre.org for more details.