From labs-no-reply@idefense.com Mon Oct 10 16:58:01 2005 From: iDEFENSE Labs To: bugtraq@securityfocus.com, vulnwatch@vulnwatch.org, full-disclosure@lists.grok.org.uk Date: Mon, 10 Oct 2005 16:54:23 -0400 Subject: [Full-disclosure] iDEFENSE Security Advisory 10.10.05: Kaspersky Anti-Virus Engine CHM File Parser Buffer Overflow Vulnerability Kaspersky Anti-Virus Engine CHM File Parser Buffer Overflow Vulnerability iDEFENSE Security Advisory 10.10.05 www.idefense.com/application/poi/display?id=318&type=vulnerabilities October 10, 2005 I. BACKGROUND Kaspersky Anti-Virus Engine (KAV) is a popular virus scanning engine for Windows and Linux. The Kaspersky Anti-Virus Engine is commonly included in various vendors' network mail gateway and host-based anti- virus products. II. DESCRIPTION Remote exploitation of a buffer overflow vulnerability in Kaspersky Labs' Anti-Virus Engine allows remote attackers to execute arbitrary code. Kaspersky Anti-Virus Engine is used by multiple vendors in Linux virus scanner products and exploitation requires minimal interaction by a targeted user. The Kasperksy Anti-Virus Engine (KAV) is found in many gateway and host-based anti-virus scanners. The vulnerability specifically exists in the CHM file parser within the KAV engine. When a corrupt CHM file is scanned by the KAV engine, a heap overflow can occur which allows remote attackers to execute arbitrary code with permissions of the anti-virus application's process, usually user privileges. On Microsoft platforms, affected software has not been shown to execute arbitrary code, however Kaspersky Anti-Virus will fail to scan any files after a corrupt CHM file has been encountered, thus allowing further malicious codes to reach the target. III. ANALYSIS Successful exploitation of the vulnerability can result in remote arbitrary code execution or the disabling of anti-virus functionality. In the case of Linux platforms, specifically network gateways, user interaction is not required and can lead to the compromise of trusted systems. In addition, compromising mail gateways can lead to further compromise of internal hosts by injecting malicious code into mail attachments. IV. DETECTION iDEFENSE Labs has confirmed the existence of this vulnerability in the following products (tested April 2005): * Kaspersky Personal 5.0.227 * Kaspersky Anti-Virus On-Demand Scanner for Linux 5.0.5 * F-Secure Anti-Virus for Linux 4.50 All products utilizing the Kaspersky Anti-Virus engine are potentially vulnerable. The vendor has notified iDEFENSE that the vulnerability has been addressed via a signature update. Users who have updated their signatures after July 2005 are reportedly not affected. V. WORKAROUND iDEFENSE is currently unaware of any effective workarounds for this issue. VI. VENDOR RESPONSE The vendor has notified iDEFENSE that the vulnerability has been addressed via a signature update. Users who have updated their signatures after July 2005 are reportedly not affected. Update your anti-virus signatures to ensure the vulnerability has been addressed. VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2005-2937 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 06/20/2005 Initial vendor notification 10/05/2005 Initial vendor response 10/10/2005 Public disclosure IX. CREDIT The discoverer of this vulnerability wishes to remain anonymous. Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp Free tools, research and upcoming events http://labs.idefense.com X. LEGAL NOTICES Copyright (c) 2005 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 email 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. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/