The *_get_synthetic_symtab functions in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.29, mishandle the failure of a certain canonicalization step, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted ELF file, related to elf32-i386.c and elf64-x86-64.c.