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@xxxxxxxxxxxxxxx ] Date of Public Advisory: 19th January 2004 Advisory number: #NISR19012005f 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 <FILENAME> 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:
<FILENAME>../../../../../windows/system32/notepad.exe?.mp3</FILENAME>
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@xxxxxxxxxxxxxxx
