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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2007.0956 -- [OSX] Apple Mail remote command execution vulnerability 28 November 2007 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Apple Mail Publisher: US-CERT Operating System: Mac OS X Impact: Execute Arbitrary Code/Commands Access: Remote/Unauthenticated Original Bulletin: http://www.kb.cert.org/vuls/id/433819 - --------------------------BEGIN INCLUDED TEXT-------------------- Vulnerability Note VU#433819 Apple Mail remote command execution vulnerability Overview Apple Mail contains a vulnerability that may allow an attacker to execute arbitrary commands on OS X Leopdard (10.5) systems. I. Description Apple OS X uses resource forks to store structured data in files. Data forks are used to store unstructured data. The AppleDouble standard is specified in RFC 1740: AppleDouble is the preferred format for a Macintosh file that is to be included in an Internet mail message, because it provides recipients with Macintosh computers the entire document, including icons and other Macintosh specific information, while other users easily can extract the Data fork (the actual data) as it is separated from the AppleDouble encoding. Apple Mail parses resource forks in mail attachments that use the MIME format AppleDouble. - From the Heise Security report: Files on a Mac can contain additional information, such as the one that another program should be used to open them. The operating system stores these in the file system in a so-called "resource fork", which is linked to the file. This type of information is usually limited to the local system; however, for emails the MIME format AppleDouble allows resource forks to be attached -- these are automatically analyzed by Apple Mail. This allows an attacker to create an email with an attachment called picture.jpg that is displayed with a JPEG icon. But when the user tries to open the picture, Apple Mail analyses the resource fork and executes a shell script, for example, without further warning. In this case, even the MIME type displays the attachment as image/jpeg, but careful Mac users may become suspicious when they see that the picture is not immediately displayed as usual. Note that to successfully exploit this vulnerability an attacker would need to convince a user to open a specially crafted email attachment with Apple Mail. Note that this vulnerability was originally addressed in APPLE-SA-2006-03-01, but was not addressed or reintroduced in Mac OS X Leopard. See US-CERT Technical Cyber Security Alert TA06-062A for more information about APPLE-SA-2006-03-01. II. Impact A remote, unauthenticated attacker may be able to execute arbitrary commands with the permissions of the user running Apple Mail. III. Solution We are currently unaware of a practical solution to this problem. Do not open unsolicited email attachments Use caution when opening email attachments. See US-CERT Cyber Security Tip ST04-010 for more information on how to safely handle email messages. Systems Affected Vendor Status Date Updated Apple Computer, Inc. Vulnerable 27-Nov-2007 References http://www.heise-security.co.uk/news/99257 http://docs.info.apple.com/article.html?artnum=303382 http://secunia.com/advisories/27785/ http://www.us-cert.gov/cas/techalerts/TA06-062A.html http://www.cert.org/homeusers/email-attachments.html http://www.apple.com/macosx/features/mail.html http://tools.ietf.org/html/rfc1740 Credit This report was based on publicly available information provided by Heise Security. This document was written by Ryan Giobbi. Other Information Date Public 25/11/2007 Date First Published 27/11/2007 09:11:46 Date Last Updated 27/11/2007 CERT Advisory CVE Name Metric 9.28 Document Revision 32 - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. 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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 iQCVAwUBR0zCEyh9+71yA2DNAQLPCwP+MIuJTPS7/MlP6Yd+V4I+vZQM1unO4rS4 19c8ZuOAhGbkGtKb175tcaQlU+1Tobl+pUi8fVbO2gZ0pBJ9ryA5L0Qz7DHbw8+J kktRUf0LSZL9LpNcMdh5UBpt1MQeM+fDX7D7DVdZ+pTD0/fReENixYbK3vETUC3u 7VYurZ4fsso= =y0SP -----END PGP SIGNATURE-----