NGSSoftware Insight Security Research Advisory

Name: RealPlayer 'ShowPreferences' Buffer Overflow Vulnerability
Systems Affected: RealPlayer 10.5 (6.0.12.1040) and older
Severity: High
Vendor URL: http://www.real.com/
Author: John Heasman [ john@ngssoftware.com ]
Date of Public Advisory: 19th January 2004
Advisory number: #NISR19012005e
Advisory URL: http://www.ngssoftware.com/advisories/real-01full.txt
Reference: http://www.ngssoftware.com/advisories/real-01.txt


Description
***********

A vulnerability has been discovered in the RealPlayer ActiveX component
which can allow remote code execution when visiting a specially crafted
webpage or when opening a specially crafted skin file.


Details
*******

The RealPlayer ActiveX component exports a function called HandleAction().
This function is designed to take a method or an action, and to execute it
under a number of differing environments. This could be within a
RealPlayer skin file or a webpage which is designed to interact with
RealPlayer.

One of the 'actions' which HandleAction() will accept is
'ShowPreferences'. This method will accept two arguments, a category and
the url of it's respective webpage.

It has been discovered that passing overly long arguments to this method
will result in an unbounded concatenation of the two arguments into a
stack based buffer through an unchecked call to sprintf().

Fix Information
***************

RealNetworks have released an update for the ShowPreferences buffer
overflow which can be downloaded from:

http://service.real.com/help/faq/security/040928_player/EN/

A check for this vulnerability has been added to Typhon III, NGSSoftware's
advanced vulnerability assessment scanner. For more information please
visit the NGSSoftware website at http://www.ngssoftware.com/


About NGSSoftware
*****************

NGSSoftware design, research and develop intelligent, advanced application
security assessment scanners. Based in the United Kingdom, NGSSoftware
have offices in the South of London and the East Coast of Scotland.
NGSSoftware's sister company NGSConsulting, offers best of breed security
consulting services, specialising in application, host and network
security assessments.

http://www.ngssoftware.com/

Telephone +44 208 401 0070
Fax +44 208 401 0076

enquiries@ngssoftware.com