iDefense Security Advisory 05.24.11 http://labs.idefense.com/intelligence/vulnerabilities/ May 24, 2011 I. BACKGROUND IBM Corp.'s Lotus Notes software is an integrated desktop client option for accessing e-mail, calendars and applications on an IBM Corp. Lotus Domino server. More information can be found by visiting the URL below.

http://www-01.ibm.com/software/lotus/ II. DESCRIPTION Remote exploitation of a stack buffer overflow vulnerability in IBM Corp.'s Lotus Notes could allow an attacker to execute arbitrary code in the context of the current user.

The vulnerability occurs during the processing of header information contained within a LZH archive file. A length calculation may cause an integer value to underflow and result in a large length value. A memory copy operation using the length value may cause LZH data to overflow the bounds of a stack buffer. This condition may lead to arbitrary code execution. III. ANALYSIS Exploitation of this vulnerability results in the execution of arbitrary code in the context of the user opening an attachment delivered via email. In order to be successful, an attacker must social engineer the victim into processing a specially crafted email attachment in a certain way. Specifically, the victim must open the attachment and click the view button on the attachment dialog box. IV. DETECTION Lotus Notes versions 6.0, 6.5, 7.0, 8.0, 8.5 are vulnerable. V. WORKAROUND A workaround is available to disable LZH archive files within the Lotus Notes file viewer:

Open the keyview.ini file in the Lotus Notes program data directory (C:\Program Files\IBM\Lotus\Notes\Data) and comment out all references to lzhsr.dll. To comment out a reference, proceed the line with a semi-colon ';'. VI. VENDOR RESPONSE IBM has released patches and workarounds to address this vulnerability. For more information, consult their advisory at the following URL. https://www-304.ibm.com/support/docview.wss?uid=swg21500034 VII. CVE INFORMATION A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not been assigned yet. VIII. DISCLOSURE TIMELINE 08/18/2010 Initial Vendor Notification 08/18/2010 Initial Vendor Reply 05/24/2011 Coordinated Public Disclosure IX. CREDIT This vulnerability was reported to iDefense by binaryhouse.net. 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 © 2011 Verisign 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.