=====[BEGIN-ACROS-REPORT]===== PUBLIC ======================================================================== = ACROS Security Problem Report #2010-08-18-1 ------------------------------------------------------------------------ - ASPR #2010-08-18-1: Remote Binary Planting in Apple iTunes for Windows ======================================================================== = Document ID: ASPR #2010-08-18-1-PUB Vendor: Apple, Inc. (http://www.apple.com) Target: Apple iTunes for Windows Impact: Remote execution of arbitrary code Severity: Very high Status: Official patch available, workarounds available Discovered by: Simon Raner of ACROS Security Current version http://www.acrossecurity.com/aspr/ASPR-2010-08-18-1-PUB.txt Summary ======= A "binary planting" vulnerability in Apple iTunes for Windows allows local or remote (even Internet-based) attackers to deploy and execute malicious code on Windows machines in the context of logged-on users. Product Coverage ================ - Apple iTunes 9.0.3.15 for Windows (at least XP, Vista and Windows 7) Note: We only tested the above version; other versions may also be affected. Analysis ======== As a result of an incorrect dynamic link library loading in Apple iTunes for Windows, an attacker can cause her malicious DLL to be loaded and executed from local drives, remote Windows shares, and even shares located on Internet. All a remote attacker has to do is plant a malicious DLL with a specific name on a network share and get the user to open a media file from this network location in iTunes - which should require minimal social engineering. Since Windows systems by default have the Web Client service running - which makes remote network shares accessible via WebDAV -, the malicious DLL can also be deployed from an Internet-based network share as long as the intermediate firewalls allow outbound HTTP traffic to the Internet. A systematic attack could deploy malicious code to a large number of Windows workstations in a short period of time, possibly as an Internet worm. Additional details are available to interested corporate and government customers under NDA, as public disclosure would reveal too many details on the vulnerability and unduly accelerate malicious exploitation. Mitigating Factors ================== - A firewall blocking outbound WebDAV traffic (in addition to blocking all Windows Networking protocols) could stop an Internet-based attack. Solution ======== Apple has issued a security bulletin [1] and published remediated versions of iTunes for Windows that fix this issue. Workaround ========== - Stopping the Web Client service could stop Internet-based attacks as long as the network firewall stops outbound Microsoft Networking protocols. This would not, however, stop remote LAN-based attacks where the attacker is able to place a malicious DLL on a network share inside the target (e.g., corporate) network. Other workarounds are available to interested corporate and government customers under NDA, as public disclosure would reveal too many details on the vulnerability and unduly accelerate malicious exploitation. Related Services ================ ACROS is offering professional consulting on this issue to interested corporate and government customers. Typical questions we can help you answer are: 1) To what extent is your organization affected by this issue? 2) Is it possible to get remote code from the Internet launched inside your network? Can this be demonstrated? 3) Have you adequately applied the remedies to remove the vulnerability? 4) Are there other workarounds that you could implement to fix this issue more efficiently and/or inexpensively? 5) Are your systems or applications vulnerable to other similar issues? Interested parties are encouraged to ask for more information at security (at) acrossecurity (dot) com. [email concealed] References ========== [1] About the security content of iTunes 9.1 http://support.apple.com/kb/HT4105 Acknowledgments =============== / Contact ======= ACROS d.o.o. Makedonska ulica 113 SI - 2000 Maribor e-mail: security (at) acrossecurity (dot) com [email concealed] web: http://www.acrossecurity.com phone: +386 2 3000 280 fax: +386 2 3000 282 ACROS Security PGP Key http://www.acrossecurity.com/pgpkey.asc [Fingerprint: FE9E 0CFB CE41 36B0 4720 C4F1 38A3 F7DD] ACROS Security Advisories http://www.acrossecurity.com/advisories.htm ACROS Security Papers http://www.acrossecurity.com/papers.htm ASPR Notification and Publishing Policy http://www.acrossecurity.com/asprNotificationAndPublishingPolicy.htm Disclaimer ========== The content of this report is purely informational and meant only for the purpose of education and protection. ACROS d.o.o. shall in no event be liable for any damage whatsoever, direct or implied, arising from use or spread of this information. All identifiers (hostnames, IP addresses, company names, individual names etc.) used in examples and demonstrations are used only for explanatory purposes and have no connection with any real host, company or individual. In no event should it be assumed that use of these names means specific hosts, companies or individuals are vulnerable to any attacks nor does it mean that they consent to being used in any vulnerability tests. The use of information in this report is entirely at user's risk. Revision History ================ August 18, 2010: Initial release Copyright ========= (c) 2010 ACROS d.o.o. Forwarding and publishing of this document is permitted providing the content between "[BEGIN-ACROS-REPORT]" and "[END-ACROS-REPORT]" marks remains unchanged. =====[END-ACROS-REPORT]=====