osTicket v1.9.12, Multiple Vulnerabilities

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# Authors: Giovanni Cerrato, Enrico Cinquini
# Vendor Homepage: http://osticket.com/
# Version: osTicket v.1.9.12

 

I. INTRODUCTION

Last version of osTicket (v1.9.12) is affected by multiple vulnerabilities.

 

II. DESCRIPTION

The web application suffers of multiple vulnerabilities.

1. Upload HTML file

It is possible to upload files attached to a ticket at URL:
https://hostname/upload/open.php

There are some controls to block not allowed file (e.g php,html) but they are only client-side and not server-side so they can be easily bypassed using tool like Burp suite.They will be uploaded and reachable at specific URL like the following example:
https://hostname/file.php?key=qycj1msethqx49ilidrwxrurvebbsipa&expires=1447372800&signature=6ee71ea7dee17cac30a884f4cf823c6734e1115d

This vulnerability could be used for example to perform XSS attack or to upload a fake login page.

2. Missing funcition level access control

It is possible to access to some contents of the web application without authentication. It is allowed to view all ticket attachment only by calling their URLs like following:
https://hostname/file.php?key=qycj1msethqx49ilidrwxrurvebbsipa&expires=1447372800&signature=6ee71ea7dee17cac30a884f4cf823c6734e1115d

This vulnerability combined with unrestricted HTML upload can be used to realize phishing and/or XSS attack via email. To achieve this tasks anyone needs to upload an HTML file containing malicious Javascript or phishing page and then spread the associated URL.

3. Stored Cross Site Scripting

The application is vulnerable to some stored XSS attack.

URL: https://hostname/scp/users.php
Functionality: Add User
Form parameter affected: Internal Notes

URL: https://hostname/scp/orgs.php
Functionality: Add Organization
Form parameter affected: Name, Internal Notes

URL https://hostname/scp/categories.php
Functionality: Add New Category
Form parameter affected: Category Description, Internal Notes

URL https://hostname/scp/departments.php
Functionality: Add New Department
Form parameter affected: Department Signature

URL: https://hostname/scp/teams.php
Functionality: Add New Team
Form parameter affected: Admin Notes, Name

URL: https://hostname/scp/groups.php
Functionality: Add New Group
Form parameter affected: Admin Notes

URL: https://hostname/scp/banlist.php
Functionality: Ban New Email
Form parameter affected: Admin Notes

URL: https://hostname/scp/profile.php
Functionality: Edit profile
Form parameter affected: Signature

A proof of concept can be obtained using the following Javascript code:
<IFRAME onload=alert(1);></IFRAME>

4. Session fixation

The application does not regenerate session id cookie (OSTSESESSID) after authentication so it is prone to session fixation attack. This vulnerability can be used to hijack a valid user session.

 

III. BUSINESS IMPACT

An attacker could upload malicious file, hijack a valid user session, perform XSS or phishing attacks and access to sensible information.

 

IV. SYSTEMS AFFECTED

Version 1.9.12 is vulnerable.

 

V. SOLUTION

It’s necessary to:

  • implement a strong upload filter to prevent the upload of malicious file
  • implement an input validation mechanism to avoid being vulnerable to XSS injection
  • review and correct access control to prevent that unauthenticated users can access to sensible documents

 

VI. ADVISORY TIMELINE

November 10th, 2015: Vulnerability identification
November 17th, 2015: First contact with vendor
November 19th, 2015: Vendor notified
November 25th, 2015: Asking for status update
November 30th, 2015: Vendor response; investigating
December 16th, 2015: Asking for status update
December 18th, 2015: Vendor says that the vulnerabilities will be fixed in the new version
January 11th, 2016: Provided more details to vendor
January 25th, 2016: Asking for status update
February 02th, 2016: Advised vendor public disclosure date will be February 04th
February 02th, 2016: Vendor provides status update(still investigating)
February 04th, 2016: Public disclosure

 

VII. LEGAL NOTICES

The information contained within this advisory is supplied “as-is” with no warranties or guarantees of fitness of use or otherwise. We accept no responsibility for any damage caused by the use or misuse of this information.