Buffer overflow in the DirectWriteFontInfo::LoadFontFamilyData function in gfx/thebes/gfxDWriteFontList.cpp in Mozilla Firefox before 43.0 might allow remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted font-family name.
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.