FreeType before 2.5.4 does not check for the end of the data during certain parsing actions, which allows remote attackers to cause a denial of service (out-of-bounds read) or possibly have unspecified other impact via a crafted Type42 font, related to type42/t42parse.c and type1/t1load.c.
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.