The IcedTea-Web plugin before 1.2.1 does not properly handle NPVariant NPStrings without NUL terminators, which allows remote attackers to cause a denial of service (crash), obtain sensitive information from memory, or execute arbitrary code via a crafted Java applet.
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.