The JPEG Image Writer in Sun Java SE in JDK and JRE 5.0 before Update 22, JDK and JRE 6 before Update 17, and SDK and JRE 1.4.x before 1.4.2_24 allows remote attackers to gain privileges via a crafted image file, related to a "quantization problem," aka Bug Id 6862968.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.