  FT_Render_Glyph( FT_GlyphSlot    slot,
                   FT_Render_Mode  render_mode )
  {
    FT_Library  library;


    if ( !slot || !slot->face )
      return FT_Err_Invalid_Argument;

    library = FT_FACE_LIBRARY( slot->face );

    return FT_Render_Glyph_Internal( library, slot, render_mode );
  }

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.