In Netwide Assembler (NASM) 2.15rc0, a heap-based buffer over-read occurs (via a crafted .asm file) in set_text_free when called from expand_one_smacro in asm/preproc.c.
Created nasm tracking bugs for this issue:
Affects: fedora-all [bug 1790847]
Nasm is an assembler/disassembler for Intel x86 architecture. This flaw can be triggered when nasm is used to assemble a malicious assembly instructions file. These operations are usually done by developers or users have local shell accounts. Also since this is an OOB read flaw, it can only cause a crash.