In Netwide Assembler (NASM) 2.14rc0, there is an illegal address access in is_mmacro() in asm/preproc.c that will cause a remote denial of service attack, because of a missing check for the relationship between minimum and maximum parameter counts.
https://usn.ubuntu.com/3694-1/
http://repo.or.cz/nasm.git/commit/c9244eaadd05b27637cde06021bac3fa1d920aa3