January 2005

ID: 00050
Ref: 46/2005
Date: 20 January 2005:13:01:38
Version: 1

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Title: Three NGSSoftware Security Advisories: 1. RealPlayer Arbitrary File Deletion Vulnerability - #NISR19012005f 2. RealPlayer Miscellaneous Vulnerabilities - #NISR19012005g 3. RealPlayer 'ShowPreferences' Buffer Overflow Vulnerability - #NISR19012005e
Abstract:
Vendors affected: NGSSoftware
Operating systems affected: NGSSoftware
Applications affected: NGSSoftware

---

Title
=====

Three NGSSoftware Security Advisories:

1. RealPlayer Arbitrary File Deletion Vulnerability - #NISR19012005f

2. RealPlayer Miscellaneous Vulnerabilities - #NISR19012005g

3. RealPlayer 'ShowPreferences' Buffer Overflow Vulnerability - #NISR19012005e

Detail
======

1. A vulnerability has been discovered in RealPlayer which can allow an attacker
to delete arbitrary files from a users system through a specially crafted
webpage with little user interaction.

2. Two vulnerabilities have been discovered in RealPlayer which may potentially
e leveraged to allow remote code execution, or may used in combination with
the Real Metadata Package File Deletion vulnerability to reliably delete
files from a users system.

3. 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.





1.



NGSSoftware Insight Security Research Advisory

Name: RealPlayer Arbitrary File Deletion 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:
Advisory URL: http://www.ngssoftware.com/advisories/real-02full.txt
Reference: http://www.ngssoftware.com/advisories/real-01.txt


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

A vulnerability has been discovered in RealPlayer which can allow an attacker
to delete arbitrary files from a users system through a specially crafted
webpage with little user interaction.


Details
*******

RealPlayer supports a proprietary package delivery file type, aptly named
Real Metadata Packages. These files contain an HTML style language which
contains information and resource urls for various packages and extensions
to RealPlayer.

One of the supported tags within the RMP file type is the tag.
This is designed to point to a relative file which is to be downloaded. If
the file which is to be downloaded already exists on the system, it will
delete this file without warning.

It is also possible to insert directory traversal character sequences in
the file name to break out of the download directory, and to point to any
existing file on the system.

Before the the deletion takes place, RealPlayer ensures that the file
extension is among those listed in the formats.ini file located at:

C:\Program Files\Real\RealPlayer\DataCache\Formats\formats.ini

It is possible to bypass this file extension check in the follow manner
due to a lack in the file extension validation process:

../../../../../windows/system32/notepad.exe?.mp3


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

RealNetworks have released an update for the Real Meta Package file deletion
vulnerability 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



2.


NGSSoftware Insight Security Research Advisory

Name: RealPlayer Miscellaneous Vulnerabilities
Systems Affected: RealPlayer 10.5 (6.0.12.1040) and older
Severity: Low/Medium
Vendor URL: http://www.real.com/
Author: John Heasman [ john@ngssoftware.com ]
Date of Public Advisory: 19th January 2004
Advisory number: #NISR19012005g
Advisory URL: http://www.ngssoftware.com/advisories/real-03full.txt
Reference: http://www.ngssoftware.com/advisories/real-01.txt

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

Two vulnerabilities have been discovered in RealPlayer which may potentially
e leveraged to allow remote code execution, or may used in combination with
the Real Metadata Package File Deletion vulnerability to reliably delete
files from a users system.

The first of which is an off-by-one vulnerability in the processing of tags
in the Real Metadata Package files. If an overly long tag is supplied, the
null byte terminating the string is written over the highest order byte of
the saved base pointer. This will cause the instruction pointer to be read
from this buffer upon the function returning.

Investigation of this issue showed that the buffer from which the instruction
pointer was being read did not appear to be under user control at any given
time in the tested scenarios, however due to the nature of the vulnerability
it is important that this is not regarded as an impossibility.

The second flaw is the way in which RealPlayer Skin file names are parsed
when the files are opened by RealPlayer. If url encoded traversal sequences
are included in the RJS filename, although RealPlayer will save the RJS file
in the 'skins' folder without decoding the filename, when it attempts to open
the file it will decode the filename, and as such can be made to read an
arbitrary file from the disk.

It does not seem possible to write arbitrary content to the system through
the use of this flaw, it may be possible to use this to determine the existence
of files on the local system, and as such could be combined with the Real
Metadata Package File Deletion flaw to reliably delete files from a users system.


Details
*******

RealPlayer supports a proprietary package delivery file type, aptly named Real
Metadata Packages. These files contain an HTML style language which contains
information and resource urls for various packages and extensions to RealPlayer.

One of the supported tags within the RMP file type is the tag.
This is designed to point to a relative file which is to be downloaded. If
the file which is to be downloaded already exists on the system, it will delete
this file without warning.

It is also possible to insert directory traversal character sequences in the
file name to break out of the download directory, and to point to any existing
file on the system.

Before the the deletion takes place, RealPlayer ensures that the file extension
is among those listed in the formats.ini file located at:

C:\Program Files\Real\RealPlayer\DataCache\Formats\formats.ini

It is possible to bypass this file extension check in the follow manner due to a
lack in the file extension validation process:

../../../../../windows/system32/notepad.exe?.mp3


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

RealNetworks have released an update for these issues 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



3.


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