Multiple Vendor libwpd Multiple Buffer Overflow Vulnerabilities iDefense Security Advisory 03.16.07 http://labs.idefense.com/intelligence/vulnerabilities/ Mar 16, 2007
I. BACKGROUND libwpd is a C++ library used to decode and encode word perfect documents. It is commonly used as a plug-in in word processing utilities such as Open Office and Abiword. For more information please visit the following URL. http://libwpd.sourceforge.net/ II. DESCRIPTION Remote exploitation of multiple buffer overflow vulnerabilities in libwpd, as included in various vendors' operating system distributions, could allow an attacker to execute arbitrary code. One problem specifically exists in the WP6GeneralTextPacket::_readContents function. This function reads in a series of integer values and sums them. This sum is then used to allocate a block of memory from the heap. The function then copies data from the file into the buffer using each operand from the addition as the number of bytes to copy. The summing operation leads to an integer overflow, and the buffer can then be overflowed by the copy operations. Two additional problems exist in the WP3TablesGroup::_readContents() and WP5DefinitionGroup_DefineTablesSubGroup::WP5DefinitionGroup_DefineTablesSubGroup() functions. These functions read an integer value from an attacker supplied file, and uses the value as a loop counter. In the loop a statically sized buffer is filled with arbitrary data from the file. This leads to an exploitable heap overflow. III. ANALYSIS Successful exploitation of these vulnerabilities requires an attacker to persuade a user into opening a specially crafted Wordperfect (WPD) document. If successful, the attacker could execute arbitrary code with the permissions of the victim. IV. DETECTION iDefense has confirmed the existence of this vulnerability in libwpd version 0.8.7. Previous versions may also be affected. This library is used by applications such as Abiword, Kword, and Open Office. V. WORKAROUND iDefense is currently unaware of any workarounds for this issue. VI. VENDOR RESPONSE The libwpd maintainers have addressed these vulnerabilities with the release of version 0.8.9. VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-0002 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 01/11/2007 Initial vendor notification 01/12/2007 Initial vendor response 03/16/2007 Coordinated public disclosure IX. CREDIT The first issue described was reported to iDefense by an anonymous researcher. Further analysis by Sean Larsson (iDefense Labs) lead to the discovery of additional problems. 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 [EMAIL PROTECTED] 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. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
