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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0067 -- NGSSoftware Insight Security Research Advisory RealPlayer Miscellaneous Vulnerabilities 20 January 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: RealPlayer 10.5 (6.0.12.1040) and prior Publisher: NGSSoftware Operating System: Windows XP Windows 2000 Windows NT Windows ME Windows 98SE Impact: Execute Arbitrary Code/Commands Delete Arbitrary Files Access: Remote/Unauthenticated Original Bulletin: http://www.ngssoftware.com/advisories/real-03full.txt - --------------------------BEGIN INCLUDED TEXT-------------------- 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 be 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 <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 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 - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBQe8nYSh9+71yA2DNAQLj7QP+NhoaR4auputlUiCGrU23ERP2JrDrkf3y 2Lu8vs82Xm7UBsfJYk9wLSnnl5sUQlcDKvnfbmSd2LaC09QTvIBaNfCsTA+qmNmo bVimM5D3lWh4vQrPLD63cCOiFKyoFh4K9Ld3b5hGE8b00uk/gxU9QXTvug8zZj5F PJrx7/VSxO4= =evK8 -----END PGP SIGNATURE-----