Mesa, as used in Google Chrome before 21.0.1183.0 on the Acer AC700, Cr-48, and Samsung Series 5 and 5 550 Chromebook platforms, and the Samsung Chromebox Series 3, allows remote attackers to execute arbitrary code via unspecified vectors that trigger an "array overflow."
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.