Computer Associates eTrust EZ Antivirus Insecure File Permission Vulnerability iDEFENSE Security Advisory 12.15.04 http://www.idefense.com/application/poi/display?id=164 December 15, 2004 I. BACKGROUND Computer Associates eTrust EZ Antivirus is antivirus protection software for home and business use. It provides complete protection, detection and elimination of thousands of computer viruses, worms, and Trojan Horse programs. II. DESCRIPTION Local exploitation of an insecure permission vulnerability in Computer Associates eTrust EZ Antivirus allows attackers to escalate privileges or disable protection. Computer Associates eTrust EZ Antivirus is a product used to protect a personal computer from virus infections. The vulnerability specifically exists in the default file Access Control List (ACL) settings that are applied during installation. When an administrator installs eTrust EZ Antivirus, the default ACL allows any user to modify the installed files. Because of the fact that some of the programs run as system services, a user can simply replace an installed eTrust EZ Antivirus file with their own malicious code that will later be executed with system privileges. One such file that would be a target for this is VetMsg.exe. III. ANALYSIS Successful exploitation allows local attackers to escalate privileges to the system level. It is also possible to use this vulnerability to simply disable protection by moving all of the executable files so that they cannot start upon a reboot. IV. DETECTION iDEFENSE has confirmed the existence of this vulnerability in eTrust EZ Antivirus version 7.0.1.4. According to Computer Associates, eTrust EZ Antivirus r7.0.0 - r7.0.4 installed on PC's running Windows NT, 2000 or XP and with NTFS formatted drives are also affected. V. WORKAROUND Apply proper Access Control List settings to the directory that eTrust EZ Antivirus is installed in. The ACL rules should make sure that no regular users can modify files in the directory. VI. VENDOR RESPONSE "With the assistance of iDEFENSE, Computer Associates has identified a medium-risk vulnerability in the installation and updating components of eTrustTM EZ Antivirus which may allow a local user to escalate their user privileges on a PC and disable protection. Effected generally available releases of eTrust EZ Antivirus include: eTrust EZ Antivirus r7.0.0 - r7.0.4 installed on PC's  - running Windows NT, 2000 or XP  - with NTFS formatted drives Computer Associates has actively addressed this issue in eTrust EZ Antivirus r7.0.5 and above. More information about this vulnerability and instructions on how to upgrade to the latest version of eTrust EZ Antivirus can be found at: http://crm.my-etrust.com/login.asp?username=guest&target=DOCUMENT&openparameter=2222 At Computer Associates, we take every report of exposure with the utmost urgency, to ensure that no customer is left in a vulnerable situation. We have assigned this vulnerability the ID number 32054." VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the names CAN-2004-1149 to these issues. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 10/26/2004 Initial vendor notification 10/29/2004 Initial vendor response 12/15/2004 Coordinated 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 X. LEGAL NOTICES Copyright © 2004 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.netsys.com/full-disclosure-charter.html