Public Vulnerability Reports

IBM Lotus Notes Client TagAttributeListCopy Buffer Overflow Vulnerability

10.23.07

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-142.ibm.com/software/sw-lotus/products/product4.nsf/wdocs/noteshomepage

DESCRIPTION

Remote exploitation of a buffer overflow vulnerability in IBM Corp.'s Lotus Notes mail user agent could allow attackers to execute arbitrary code in the context of the current user.

When a Lotus Notes user receives an HTML email, the HTML is converted to a format resembling RTF (Rich Text Format). When messages are replied to, forwarded or copied to the clipboard, the e-mail format is converted again.

The buffer overflow is the result of a call to "Cstrcpy" when copying an attacker supplied variable length string into a fixed-sized stack buffer. The overflow occurs at the "Cstrcpy" call inside the "TagAttributeListCopy" function in nnotes.dll.

ANALYSIS

Exploitation allows attackers to execute arbitrary code in the context of the recipient of the message. In order to be successful, an attacker must social engineer the victim into processing a specially crafted message in a certain way. Specifically, the victim must either forward, reply with history, or copy the message to the clipboard in order to trigger the vulnerability.

Additionally, non-printable ASCII characters are converted to the LMBCS (Lotus MultiByte Character Set) before the overflow occurs. This complicates, but does not prevent, exploitation.

DETECTION

iDefense confirmed the existence of this vulnerability in version 7.0.2 of IBM Corp.'s Lotus Notes. Additionally, versions 6.5.1, 6.5.3 and 7.0.1 were reported to be vulnerable. Other versions are suspected to be vulnerable.

WORKAROUND

iDefense is currently unaware of any effective workaround for this issue.

VENDOR RESPONSE

IBM Lotus has addressed this vulnerability within versions 7.0.3 and 8.0 of Lotus Notes. For more information, visit the following URL.

http://www-1.ibm.com/support/docview.wss?rs=477&uid=swg21272930

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-4222 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

02/07/2007 Initial vendor notification
02/07/2007 Initial vendor response
10/23/2007 Coordinated public disclosure

CREDIT

This vulnerability was reported to iDefense by UVInc.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

LEGAL NOTICES

Copyright © 2007 Verisign, 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 customer service 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.