Lame

Personal Rating: Very Easy

Enumeration

I ran an extensive nmap scan:

sudo nmap -A -p- <IP>

Starting Nmap 7.92 ( https://nmap.org ) at 2021-10-05 09:48 CEST
Nmap scan report for 10.10.10.3
Host is up (0.19s latency).
Not shown: 996 filtered tcp ports (no-response)
PORT    STATE SERVICE     VERSION
21/tcp  open  ftp         vsftpd 2.3.4
| ftp-syst: 
|   STAT: 
| FTP server status:
|      Connected to 10.10.16.2
|      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
|      vsFTPd 2.3.4 - secure, fast, stable
|_End of status
|_ftp-anon: Anonymous FTP login allowed (FTP code 230)
22/tcp  open  ssh         OpenSSH 4.7p1 Debian 8ubuntu1 (protocol 2.0)
| ssh-hostkey: 
|   1024 60:0f:cf:e1:c0:5f:6a:74:d6:90:24:fa:c4:d5:6c:cd (DSA)
|_  2048 56:56:24:0f:21:1d:de:a7:2b:ae:61:b1:24:3d:e8:f3 (RSA)
139/tcp open  netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp open  netbios-ssn Samba smbd 3.0.20-Debian (workgroup: WORKGROUP)
Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
Aggressive OS guesses: Linux 2.6.23 (92%), Belkin N300 WAP (Linux 2.6.30) (92%), Control4 HC-300 home controller (92%), Dell Integrated Remote Access Controller (iDRAC5) (92%), Dell Integrated Remote Access Controller (iDRAC6) (92%), Linksys WET54GS5 WAP, Tranzeo TR-CPQ-19f WAP, or Xerox WorkCentre Pro 265 printer (92%), Linux 2.4.21 - 2.4.31 (likely embedded) (92%), Citrix XenServer 5.5 (Linux 2.6.18) (92%), Linux 2.6.18 (ClarkConnect 4.3 Enterprise Edition) (92%), Linux 2.6.8 - 2.6.30 (92%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 2 hops
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel

Host script results:
| smb-security-mode: 
|   account_used: <blank>
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)
|_smb2-time: Protocol negotiation failed (SMB2)
| smb-os-discovery: 
|   OS: Unix (Samba 3.0.20-Debian)
|   Computer name: lame
|   NetBIOS computer name: 
|   Domain name: hackthebox.gr
|   FQDN: lame.hackthebox.gr
|_  System time: 2021-10-05T03:51:17-04:00
|_clock-skew: mean: 2h01m51s, deviation: 2h49m43s, median: 1m50s

TRACEROUTE (using port 445/tcp)
HOP RTT       ADDRESS
1   194.07 ms 10.10.16.1
2   273.26 ms 10.10.10.3

The anonymous FTP login was a dead end as there was only an empty folder. Running further enumeration on the smb port shew very interesting results though:

|   LAME\user (RID: 3002)
|     Full name:   just a user,111,,
|     Flags:       Normal user account

|   LAME\msfadmin (RID: 3000)
|     Full name:   msfadmin,,,
|     Flags:       Normal user account

| smb-ls: Volume \\10.10.10.3\tmp
| SIZE   TIME                 FILENAME
| <DIR>  2021-10-05T08:12:02  .
| <DIR>  2020-10-31T06:33:58  ..
| <DIR>  2021-10-05T07:47:13  vmware-root
| 0      2021-10-05T07:48:19  5563.jsvc_up
| 1600   2021-10-05T07:47:13  vgauthsvclog.txt.0

|   \\10.10.10.3\ADMIN$: 
|     Type: STYPE_IPC
|     Comment: IPC Service (lame server (Samba 3.0.20-Debian))
|     Users: 1
|     Max Users: <unlimited>
|     Path: C:\tmp
|     Anonymous access: <none>

|   \\10.10.10.3\IPC$: 
|     Type: STYPE_IPC
|     Comment: IPC Service (lame server (Samba 3.0.20-Debian))
|     Users: 1
|     Max Users: <unlimited>
|     Path: C:\tmp
|     Anonymous access: READ/WRITE

|   \\10.10.10.3\opt: 
|     Type: STYPE_DISKTREE
|     Comment: 
|     Users: 1
|     Max Users: <unlimited>
|     Path: C:\tmp
|     Anonymous access: <none>

|   \\10.10.10.3\print$: 
|     Type: STYPE_DISKTREE
|     Comment: Printer Drivers
|     Users: 1
|     Max Users: <unlimited>
|     Path: C:\var\lib\samba\printers
|     Anonymous access: <none>

|   \\10.10.10.3\tmp: 
|     Type: STYPE_DISKTREE
|     Comment: oh noes!
|     Users: 1
|     Max Users: <unlimited>
|     Path: C:\tmp
|_    Anonymous access: READ/WRITE

SMB Exploits w/ Metasploit

Searching for a useful module in msfconsole, I tried multi/samba/usermap_script, which worked.

Then I found a CVE for the smb verison on the server, Samba 3.0.20-Debia. The according metasploit module gave me a root shell immediately. This could have been done with a PoC from searchsploit or exploitdb.