Veritas Backup Exec Agent Browser Registration Request Buffer Overflow Vulnerability iDEFENSE Security Advisory 12.16.04 http://www.idefense.com/application/poi/display?id=169 December 16, 2004 I. BACKGROUND Backup Exec is a next generation backup and restore solution for Microsoft Windows server environments. More information is available here: http://veritas.com/Products/www?c=product&refId=57 II. DESCRIPTION Remote exploitation of a stack-based buffer overflow vulnerability in Veritas Backup Exec allows attackers to execute arbitrary code. The vulnerability specifically exists within the function responsible for receiving and parsing registration requests. The registration request packet contains the hostname and connecting TCP port of the client which is stored in an array on the stack. An attacker can send a registration request with an overly long hostname value to overflow the array and take control of the saved return address to execute arbitrary code. III. ANALYSIS Successful exploitation does not require authentication thereby allowing any remote attacker to execute arbitrary code under the privileges of the Backup Exec Agent Browser (benetns.exe) process which is usually a domain administrative account. IV. DETECTION iDEFENSE has confirmed the existence of this vulnerability in Backup Exec for Windows Servers 9.1. V. WORKAROUND Use a firewall to restrict incoming connections to trusted workstations running the Backup Exec client software. VI. VENDOR RESPONSE 8.60.3878 Hotfix 68 - Backup Exec (Buffer overflow creates a security hole in Agent Browser) http://seer.support.veritas.com/docs/273422.htm 9.1.4691 Hotfix 40 - Backup Exec (Buffer overflow creates a security hole in Agent Browser; Licensed Storage Central becomes Eval when Backup Exec 9.1 is uninstalled) *Requires Backup Exec 9.1.4691 Service Pack 1 http://seer.support.veritas.com/docs/273420.htm VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the names CAN-2004-1172 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 11/02/2004 Initial vendor contact 12/16/2004 Initial vendor response 12/16/2004 Public disclosure IX. CREDIT An anonymous contributor and Patrik Karlsson (http://www.cqure.net) are credited with discovering this vulnerability. Get paid for vulnerability research http://www.idefense.com/poi/teams/vcp.jsp X. LEGAL NOTICES Copyright (c) 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.