Palm Pre WebOS 1.0.4 Remote execution of arbitrary HTML code vulnerability

I. Description

The Palm Pre WebOS version 1.0.4 and below allows a remote attacker to execute arbitrary HTML code on
the phone via certain applications. The affected applications involve the native email client via the
notifications system as well as the native calendar application.

The vendor has been contacted and a patch has been released:

WebOS 1.1 - http://kb.palm.com/wps/portal/kb/na/pre/p100eww/sprint/solutions/article/50607_en.html#11

II. Impact

Email Notification System:

A remote attacker is able to construct a malicious email that will cause the Palm Pre WebOS to execute
arbitrary HTML code if the notification system is enabled. Upon receiving a malicious email where the
FROM field contains HTML code, the Palm Pre WebOS will issue a user a notification that an email has
arrived and execute the HTML code of the attacker’s choice. This vulnerability does not require user
interaction.

Calendar Application:

A remote attacker can create a malicious calendar event putting arbitrary HTML code inside the
event/title field that can be executed without user interaction. To trigger this vulnerability, any of
the following conditions can occur:

1. The victim Views the Calendar event and the malicious HTML will be executed.
2. The victim enables a reminder notice for the malicious calendar event, upon being notified of the
   reminder, the
   malicious HTML code will be executed.
3. The calendar event triggers and the malicious HTML code will be executed.

In cases where calendar events can be sent to users without interaction/acceptance, the risk of this
vulnerability is higher.

III. Proof of Concept

The following HTML code can be used to provide a proof of concept for each of the vulnerabilities
listed in this advisory:

"Test <META http-equiv="refresh" content="1;URL=http://www.google.com">"

IV. About

This vulnerability was discovered by Townsend Ladd Harris PalmPreHacker[at]gmail.com

Details of this vulnerability can be found at:
http://tlhsecurity.blogspot.com/2009/08/palm-pre-webos-104-remote-execution-of.html