WinPcap Input Validation Flaw in NPF.SYS Driver Lets Local Users Gain Elevated Privileges
SecurityTracker Alert ID: 1018350|
SecurityTracker URL: http://securitytracker.com/id/1018350
(Links to External Site)
Updated: May 6 2008|
Original Entry Date: Jul 10 2007
Execution of arbitrary code via local system, Root access via local system|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): 4.x prior to 4.1|
A vulnerability was reported in WinPcap. A local user can obtain system privileges on the target system.|
A local user can exploit an input validation flaw in the NPF.SYS driver to execute arbitrary code on the target system with kernel-level privileges.
Interrupt Request Packet parameters passed to IOCTL 9031 (BIOCGSTATS) are affected.
The vendor was notified on May 16, 2007.
Mario Ballano from 48bits.com reported this vulnerability to iDefense.
A local user can obtain kernel-level privileges on the target system.|
The vendor has issued a fixed version (4.0.1).|
The vendor's advisory is available at:
Vendor URL: www.winpcap.org/ (Links to External Site)
Input validation error|
|Underlying OS: Windows (Any)|
Source Message Contents
Subject: iDefense Security Advisory 07.09.07: WinPcap NPF.SYS Local Privilege|
WinPcap NPF.SYS Local Privilege Escalation Vulnerability
iDefense Security Advisory 07.09.07
Jul 09, 2007
WinPcap is a software package that facilitates real-time link-level
network access for Windows-based operating systems. It is used by a
wide range of open-source projects including Wireshark. More
information is available at the project web site at the URL shown
Local exploitation of an input validation vulnerability within the
NPF.SYS device driver of WinPcap allows attackers to execute arbitrary
code in kernel context.
The vulnerability specifically exists due to insufficient input
validation when handling the Interrupt Request Packet (Irp) parameters
passed to IOCTL 9031 (BIOCGSTATS). By passing carefully chosen
parameters to this IOCTL, an attacker can overwrite arbitrary kernel
Exploitation allows attackers to execute arbitrary code in kernel
The vulnerable device driver is loaded when WinPcap is initialized. This
driver can be set to load on start-up depending on a choice made at
installation time. This is not the default setting.
In a default installation, the device driver is not loaded until an
Administrator utilizes a WinPcap dependent application. Once they do,
it will become accessible to normal users as well. When a program using
this driver exists, it is not unloaded. Attackers will continue to have
access until the driver is manually unloaded.
If the option to allow normal user access was chosen at installation
time, attackers will always have access to this device driver.
Consequently, a local attacker without administrator privileges would
have access to sniff, as well as exploit this vulnerability.
iDefense has confirmed the existence of this vulnerability in version
4.0 of WinPcap as included in Wireshark 0.99.5. The version of NPF.SYS
tested was 126.96.36.1995. Older versions are suspected to be vulnerable.
iDefense is currently unaware of any effective workaround for this
VI. VENDOR RESPONSE
The WinPcap Team has addressed this vulnerability by releasing version
4.0.1 of the WinPcap software. For more information, see the following
VII. CVE INFORMATION
A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.
VIII. DISCLOSURE TIMELINE
05/16/2007 Initial vendor notification
05/16/2007 Initial vendor response
07/09/2007 Coordinated public disclosure
This vulnerability was reported to iDefense by Mario Ballano from
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