iDefense Security Advisory 05.12.08 http://labs.idefense.com/intelligence/vulnerabilities/ May 12, 2008 I. BACKGROUND Intelligent Input/Output (I2O) is a defunct computer input/output (I/O) specification. i2omgmt.sys is a Windows driver for the I2O Utility Filter. For more background information about I2O, see following website. http://en.wikipedia.org/wiki/I2O II. DESCRIPTION Local exploitation of an input validation vulnerability within version 5.1.2600.2180 of i2omgmt.sys, as included with Microsoft Corp's Windows XP operating system, could allow an attacker to execute arbitrary code in the context of the kernel. This vulnerability specifically exists due to insecure permissions on the \\.\I2OExc device interface. The permissions on this device allow "Everyone" write access. This could allow a locally logged-in user to access functionality designed for privileged use only. Additionally, the IOCTL handlers for this device interface do not properly validate user-mode buffer passed to them, so an attacker can supply a fake DeviceObject pointer to a user-mode address. As such, it is possible to overwrite arbitrary memory or execute attacker-supplied code in the context of the kernel. III. ANALYSIS Exploitation allows an attacker to elevate privileges by overwriting arbitrary system memory or executing code within kernel context. An attacker needs to log-in to the target machine to exploit this vulnerability. This driver is related to I2O protocol and RAID devices. It is not present by default on every Windows installation. However, iDefense found this driver loaded on several systems we tested. IV. DETECTION iDefense has confirmed the existence of this vulnerability in i2omgmt.sys version 5.1.2600.2180 as installed on some Windows XP SP2 systems. All other Windows releases with this driver, including previous versions, are suspected to be vulnerable. V. WORKAROUND Removing write permissions for "Everyone" appears to prevent access to the vulnerable code. Although no side effects were witnessed in lab tests, normal functionality may be hindered. VI. VENDOR RESPONSE Microsoft has addressed this issue within Windows XP Service Pack 3. To obtain Microsoft XP Service Pack 3, visit the following URL. http://www.microsoft.com/downloads/details.aspx?FamilyID=5b33b5a8-5e76-401f-be08-1e1555d4f3d4 VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-0322 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 03/20/2007 Initial vendor notification 03/20/2007 Initial vendor response 05/12/2008 Coordinated public disclosure IX. CREDIT This vulnerability was reported to iDefense by Rubén Santamarta of reversemode.com. 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 © 2008 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 customerservice@xxxxxxxxxxxx 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.