An issue was discovered in yasm version 1.3.0. There is a NULL pointer dereference in nasm_parser_directive() in modules/parsers/nasm/nasm-parse.c.
https://github.com/yasm/yasm/issues/167
https://gist.github.com/Clingto/bb632c0c463f4b2c97e4f65f751c5e6d