Babylon Cross-Application Scripting Code Execution

[Roee Hay <ROEEH@xxxxxxxxxx>]

Introduction
============
Babylon is a single-click computer online dictionary and translation
software
which is also capable of translating whole documents and web pages. The
translation and dictionary results are presented to the user via the
Trident
layout engine (an in-app/embedded Internet-Explorer rendering engine).

Vulnerability
=============
Babylon fails to sanitize user input before rendering it on the Trident
control,
effectively leading to a Cross-Application Scripting vulnerability.

The user's input can originate from the following sources:

1. Babylon's main translation interface: When searching for a non-existent
   term Babylon pushes the string "No matches were found for 'non-existent
   term'. Search the web for non-existent-term". Unfortunately,
'non-existent
   term' is not HTML encoded or validated before it is written on the
embedded
   browser (the translation process transparently validates translatable
input).

2. Document translation: Documents (such as PDF files) may contain text
which
   cannot be translated (e,g. JavaScript code), in such case it is rendered
   without HTML encoding or validation.

3. Web site translation: Same as the document translation case. Text which
is
   not translated is simply rendered on the Trident control. In order to
trigger
   an attack, the victim has to be lured into translating malicious text,
either
   in a document or on a web page. Although the scenarios require some
   social-engineering, some of them are feasible and realistic.

Impact
======
The Trident control runs in Local Machine Zone (LMZ) which is not Locked
down.

This allows a malicious script to perform the following actions:

1. Interact with other websites in the background while using persistent
cookies
   to impersonate the victim: This can be done using XHR. The payload can
leak
   the response's body which may contain sensitive information in case the
   victim has been authenticated on the site prior to the attack. The
payload
   can also perform actions on the site on behalf of the victim.

2. Collect information from local files: This can be done using XHR or by a
   hidden iframe with the filename's as the source. Since the payload runs
in a
   non-Locked-down LMZ, the XHR response or iframe's body can be inspected
and
   sent back to the attacker.

3. Code execution: System commands can be executed by using the
Wscript.Shell
   ActiveX object to practically take over the whole system.

Vulnerable versions
===================
Versions prior to 8.0.7 are susceptible to this vulnerability.

Credit
======
Yair Amit <amityair@xxxxxxxxxx>
Roee Hay <roeeh@xxxxxxxxxx>

Acknowledgments
===============
We would like to thank the Babylon team for their quick responses and the
efficient way in which they handled this security issue.

References
==========
1. Original advisory:
   http://blog.watchfire.com/files/babylon_cas_advisory.pdf
2. Blog post:

http://blog.watchfire.com/wfblog/2010/11/babylon-cross-application-scripting.html

3. Demo:
   http://www.youtube.com/watch?v=51ypgI1lqzE
4. Babylon's homepage:
   http://www.babylon.com/
5. Enhanced Browsing Security:
   http://technet.microsoft.com/en-us/library/bb457150.aspx