From idlabs-advisories@idefense.com Tue Aug 3 22:14:01 2004 From: idlabs-advisories@idefense.com To: idlabs-advisories@idefense.com Date: Tue, 3 Aug 2004 13:58:22 -0400 Reply-To: customerservice@idefense.com Subject: [Full-Disclosure] iDEFENSE Security Advisory 08.03.04b: NGSEC StackDefender 2.0 Invalid Pointer Dereference Vulnerability NGSEC StackDefender 2.0 Invalid Pointer Dereference Vulnerability iDEFENSE Security Advisory 08.03.04b www.idefense.com/application/poi/display?id=119&type=vulnerabilities August 3, 2004 I. BACKGROUND StackDefender is an IPS (Intrusion Prevention System), for Win32 platforms, that will deny shellcode from executing in User Stack and Writable memory regions. StackDefender uses PAX technology for this purpose. II. DESCRIPTION StackDefender offers protection by hooking ZwAllocateVirtualMemory and ZwProtectVirtualMemory functions. These two kernel API's are responsible for allocating and protecting memory. The ZwProtectVirtualMemory function declaration is as follows: ZwProtectVirtualMemory(HANDLE ProcessHandle, PVOID *BaseAddress, PULONG ProtectSize, ULONG NewProtect, PULONG OldProtect); The problem specifically exists because StackDefender fails to verify 'BaseAddress' as a valid address prior dereferencing it as a pointer. III. ANALYSIS Successful exploitation allows remote attackers to cause the underlying system to crash. This is possible by specifying an invalid address for 'BaseAddress'. Exploitation requires that an attacker has an exploitation vector to the system that StackDefender attempts to block. IV. DETECTION iDEFENSE has confirmed the existence of this vulnerability in the latest version of StackDefender, version 2.0. V. WORKAROUND iDEFENSE is currently unaware of any workarounds for this issue. VI. VENDOR FIX The vendor has released the following patch fixing this issue: http://www.ngsec.com/downloads/stackdefender/StackDefender-2.10.exe VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2004-0766 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 07/10/2004 Vulnerability discovered by iDEFENSE 07/12/2004 Initial vendor notification 07/22/2004 Initial vendor response 08/03/2004 Public disclosure IX. CREDIT Peter Silberman (iDEFENSE Labs) is credited with the discovery of 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. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html