=======
Summary
=======
Name: Heap overflow in RealPlayer ID3 tag parsing code
Release Date: 29 October 2007
Reference: NGS00432
Discover: John Heasman <john@ngssoftware.com>
Vendor: RealNetworks
Systems Affected: Several builds of RealPlayer 10.5,
  All builds of RealPlayer 10.
  For additional affected versions, see the URL below.
Risk: High
Status: Published

========
TimeLine
========
Discovered:  1 August 2006
Released:  1 August 2006
Approved:  1 August 2006
Reported:  1 August 2006
Fixed: 25 October 2007
Published: 29 October 2007

===========
Description
===========
There is a heap overflow in the Realplayer code that parses ID3 tags in
MP3 files.

Impact: attackers could execute code of their choice on susceptible
systems if a user were induced to open a malicious MP3 file.

=================
Technical Details
=================
The problem stems from the parsing of a Lyrics3 v2.00 tag.  The size of
the tag is calculated by reading 5 ASCII characters and calling
pncrt.atoi.  A buffer is then allocated on the heap of size tag length +
1.  Since atoi parses a signed integer, supplying -1, results in a zero
length allocation into which data is copied.

This can be exploited to overwrite a function pointer leading to the
execution of arbitrary attacker-supplied code in the context of the user
under which RealPlayer is running.

===============
Fix Information
===============
This issue has now been resolved.  Steps detailing how to update 
RealPlayer may be obtained from:

http://service.real.com/realplayer/security/10252007_player/en/


NGSSoftware Insight Security Research
http://www.ngssoftware.com/
http://www.databasesecurity.com/
http://www.nextgenss.com/
+44(0)208 401 0070

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