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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0200 -- iDEFENSE Security Advisory 03.01.05 RealNetworks RealPlayer .smil Buffer Overflow Vulnerability 4 March 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: RealPlayer RealOne Player HelixPlayer Publisher: iDEFENSE Operating System: Linux variants Windows Mac OS X Impact: Execute Arbitrary Code/Commands Access: Remote/Unauthenticated CVE Names: CAN-2005-0455 Original Bulletin: http://service.real.com/help/faq/security/050224_player/EN/ http://www.idefense.com/application/poi/display?id=209 Comment: This bulletin concerns a vulnerability in various RealNetworks products' handling of SMIL files. Handling of WAV files contain similar vulnerabilities. Both of these problems are fixed in the latest version of these products. Please see the original RealNetworks bulletin above for more information. - --------------------------BEGIN INCLUDED TEXT-------------------- RealNetworks RealPlayer .smil Buffer Overflow Vulnerability iDEFENSE Security Advisory 03.01.05 www.idefense.com/application/poi/display?id=209&type=vulnerabilities March 1, 2005 I. BACKGROUND RealPlayer is an application for playing various media formats, developed by RealNetworks Inc. For more information, visit http://www.real.com/. II. DESCRIPTION Remote exploitation of a stack-based buffer overflow vulnerability in the The Synchronized Multimedia Integration Language (smil) file format parser within various versions of RealNetworks Inc.'s RealPlayer could allow attackers to execute arbitrary code. The vulnerability specifically exists due to an unbounded string copying operation. The vulnerable code is shown below: datatype/smil/renderer/smil1/smlparse.cpp CSmil1Parser::testAttributeFailed(SMIL1Node* pNode) line 2878 *** if(HXR_OK == rc) { UINT32 ulScreenHeight = 0; UINT32 ulScreenWidth = 0; const char* pScreenSize = (const char*)pBuf->GetBuffer(); // format is screen-height "X" screen-width char tmp[256]; /* Flawfinder: ignore */ strcpy(tmp, pScreenSize); /* Flawfinder: ignore */ *** The pBuf object's datapointer (which is what GetBuffer uses internally) is pointing at the screen-size attribute in the user-supplied smil file. This allows a fixed stack buffer to be overwritten with user-supplied data. An attacker could use this stack overwrite to manipulate a saved return address or Structured Exception Handler, allowing for arbitrary code execution. In order to trigger this vulnerability, one would need an otherwise valid .smil file with the following line added in an appropriate section: <text src="1024_768.en.txt" region="size" system-screen- size="LONGSTRINGX768"> Note that "LONGSTRING" should be more than 256 bytes in order to cause stack corruption. III. ANALYSIS Exploitation allows for arbitrary code execution as the user who opened the .smil file. Exploitation requires an attacker to craft a malicious .smil and convince a user to open it. An attacker could also force a web browser to refresh and automatically load the .smil file from a normal web page under the attacker's control. In default installations of RealPlayer under Windows, Internet Explorer will not prompt the user for an action when encountering a .smil file. It will open it without delay, thus allowing a more effective method of exploitation. IV. DETECTION iDEFENSE Labs has confirmed that Real Networks Inc.'s RealPlayer 10.5 (6.0.12.1056) on Windows and RealPlayer 10 (10.0.1.436) on Linux are vulnerable. The vendor has reported that the following products are vulnerable on the following platforms: Windows: RealPlayer 10.5 (6.0.12.1056 and below) RealPlayer 10 RealOne Player V2 RealOne Player V1 RealPlayer 8 RealPlayer Enterprise Mac RealPlayer 10 (10.0.0.325 and below) RealOne Player Linux RealPlayer 10 Helix Player V. WORKAROUND There are no known workarounds for this vulnerability. Although .smil files can be disassociated from RealPlayer, it is still possible to cause these files to load with RealPlayer using other methods. One such method is loading the file via one of the many ActiveX Controls that RealPlayer contains. Any effective workaround would prevent RealPlayer from functioning. VI. VENDOR RESPONSE A vendor advisory for this issue is available at: http://service.real.com/help/faq/security/050224_player VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the names CAN-2005-0455 to these issues. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 01/14/2005 Initial vendor notification 01/19/2005 Initial vendor response 03/01/2005 Coordinated public disclosure IX. CREDIT The discoverer of this vulnerability wishes to remain anonymous. Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp Free tools, research and upcoming events http://labs.idefense.com X. LEGAL NOTICES Copyright (c) 2005 iDEFENSE, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDEFENSE. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please email customerservice@idefense.com for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. - --------------------------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 iQCVAwUBQie53Sh9+71yA2DNAQJjggP/ViP5n483zenFav2o4Ceqko2ddzYcRFv7 pdc7vVj1AUOMItIS3e2mUl1p/9DGDLt1pbqqkmt0O5VTczHXyISCIdGzOmLFC8DA 8Nm6TJbjvu99wXRZP+X4FNJA7EwA58+bRNBJjYYdFKpkVRagcNOXGKhTVfs2oW9P /H/3W0yhSes= =Snrs -----END PGP SIGNATURE-----