CTF-Writeups/TryHackMe/Anonymous.md
2020-12-11 17:31:41 -05:00

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# TryHackMe-Anonymous
## NMAP
```
Nmap scan report for 10.10.126.173
Host is up (0.41s latency).
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 2.0.8 or later
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
|_drwxrwxrwx 2 111 113 4096 Jun 04 2020 scripts [NSE: writeable]
| ftp-syst:
| STAT:
| FTP server status:
| Connected to ::ffff:10.2.54.209
| Logged in as ftp
| TYPE: ASCII
| No session bandwidth limit
| Session timeout in seconds is 300
| Control connection is plain text
| Data connections will be plain text
| At session startup, client count was 4
| vsFTPd 3.0.3 - secure, fast, stable
|_End of status
22/tcp open ssh OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 8b:ca:21:62:1c:2b:23:fa:6b:c6:1f:a8:13:fe:1c:68 (RSA)
| 256 95:89:a4:12:e2:e6:ab:90:5d:45:19:ff:41:5f:74:ce (ECDSA)
|_ 256 e1:2a:96:a4:ea:8f:68:8f:cc:74:b8:f0:28:72:70:cd (ED25519)
139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp open netbios-ssn Samba smbd 4.7.6-Ubuntu (workgroup: WORKGROUP)
Service Info: Host: ANONYMOUS; OS: Linux; CPE: cpe:/o:linux:linux_kernel
Host script results:
|_clock-skew: mean: 0s, deviation: 1s, median: -1s
|_nbstat: NetBIOS name: ANONYMOUS, NetBIOS user: <unknown>, NetBIOS MAC: <unknown> (unknown)
| smb-os-discovery:
| OS: Windows 6.1 (Samba 4.7.6-Ubuntu)
| Computer name: anonymous
| NetBIOS computer name: ANONYMOUS\x00
| Domain name: \x00
| FQDN: anonymous
|_ System time: 2020-12-11T21:44:31+00:00
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
| smb2-security-mode:
| 2.02:
|_ Message signing enabled but not required
| smb2-time:
| date: 2020-12-11T21:44:31
|_ start_date: N/A
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 54.45 seconds s
```
From the nmap scan we can anonymously login into ftp since it's enabled
## FTP (PORT 21)
<img src="https://imgur.com/lgkDur4.png"/>
<img src="https://imgur.com/orbnWlZ.png"/>
These are the files that we see on the ftp server
<img src="https://imgur.com/Vc3APQQ.png"/>
There wasn't anything on the ftp server so just a Rabbit Hole...but there is another port open which is `SMB` on port 445 and by running `smbmap` to check if `anonymous` user read any share
<img src="https://imgur.com/Rwq5D7A.png"/>
So it looks like we can read share `pics` on the box , now we are going to use `smbclient` to access that share
<img src="https://imgur.com/v2TfQwl.png"/>
We only have two image files `.jpg` and `.jpeg`
<img src="https://imgur.com/nw9vyJk.png"/>
And through `strings` and `steghide` I couldn't find anything, But then I thought about that ftp server and went back and it had all permissions setup means that we can write files on it so I edited the `clean.sh` and put a bash reverse sehll in it
<img src="https://imgur.com/XUoA7M5.png"/>
Then putted it on the ftp server and I saw that `removed_files.log` is modified so when downloaded it to see what changes happened it I got a reverse shell on my netcat
Now I ran a find command to look for SUID's
<img src="https://imgur.com/QTu3Vtv.png"/>
<img src="https://imgur.com/rJpXRGd.png"/>
Here I found that `env` has a SUID so I visited `GTFOBIN` to see I can become root with it
<img src="https://imgur.com/zR9e4PF.png"/>
So we can become root , let's put this into practice
<img src="https://imgur.com/H72GLZQ.png"/>
This could have also been done with `lxd` but for that you have to make image , transfer to target then run 4-5 commands and I was lazy to do that so we got root that's the only thing that matters ( :