Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2007.1028 -- [OSX] Apple Mac OS X mount_smbfs Stack Based Buffer Overflow Vulnerability 19 December 2007 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: mount_smbfs Publisher: iDefense Operating System: Mac OS X Impact: Root Compromise Access: Existing Account CVE Names: CVE-2007-3876 Original Bulletin: http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=633 - --------------------------BEGIN INCLUDED TEXT-------------------- iDefense Security Advisory 12.17.07 http://labs.idefense.com/intelligence/vulnerabilities/ Dec 17, 2007 I. BACKGROUND The mount_smbfs utility is used to mount a remote SMB share locally. It is installed set-uid root, so as to allow unprivileged users to mount shares, and is present in a default installation on both the Server and Desktop versions of Mac OS X. For more information visit the following URL. http://developer.apple.com/documentation/Darwin/Reference/ManPages/man8/mount_smbfs.8.html II. DESCRIPTION Local exploitation of a stack based buffer overflow vulnerability in Apple Inc.'s Mac OS X mount_smbfs utility could allow an attacker to execute arbitrary code with root privileges. The vulnerability exists in a portion of code responsible for parsing command line arguments. When processing the -W option, which is used to specify a workgroup name, the option's argument is copied into a fixed sized stack buffer without any checks on its length. This leads to a trivially exploitable stack based buffer overflow. III. ANALYSIS Exploitation of this vulnerability results in the execution of arbitrary code with root privileges. In order to exploit this vulnerability, an attacker must have execute permission for the set-uid root mount_smbfs binary. IV. DETECTION iDefense has confirmed the existence of this vulnerability in Mac OS X version 10.4.10, on both the Server and Desktop versions. Previous versions may also be affected. V. WORKAROUND Removing the set-uid bit from the mount_smbfs binary will prevent exploitation. However, non-root users will be unable to use the program. VI. VENDOR RESPONSE Apple addressed this vulnerability within their Mac OS X 2007-009 security update. More information is available at the following URL. http://docs.info.apple.com/article.html?artnum=307179 VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-3876 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 07/16/2007 Initial vendor notification 07/17/2007 Initial vendor response 12/17/2007 Coordinated public disclosure IX. CREDIT This vulnerability was discovered by Sean Larsson of VeriSign iDefense Labs. Get paid for vulnerability research http://labs.idefense.com/methodology/vulnerability/vcp.php Free tools, research and upcoming events http://labs.idefense.com/ X. LEGAL NOTICES Copyright © 2007 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 e-mail 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 iQCVAwUBR2injCh9+71yA2DNAQJnGAP+ORKySzFRg+4MSpj7QGfrEAj205HUU7K2 6cxRzZJphzVIzBjO1POBKobHIOEc0f2+tA5lXcceXrggIQFr2tM2NDSbNr7enWCD nSnXe7/1RzlJddUfy3K8yPeYWzEwMyuWRQUUnr59exLm9ljGBmS2JnOmjBbjikRQ Zt++F5RO+PE= =N3ft -----END PGP SIGNATURE-----