Public Vulnerability Reports

Novell NetWare Client nicm.sys Local Privilege Escalation Vulnerability

09.01.08

BACKGROUND

The Novell Client software provides a workstation with access to Novell NetWare networks as well as Novell Open Enterprise Server (OES) services. Novell Clients can access the full range of Novell services such as authentication via Novell eDirectory, network browsing and service resolution, and secure and reliable file system access. More information about the Novel Client can be found on the vendor's web site at the following URL.

http://www.novell.com/products/clients/

DESCRIPTION

Local exploitation of an input validation error vulnerability within Novell Inc.'s NetWare Client allows attackers to execute arbitrary code within the kernel.

When the Novell NetWare Client is installed on a Windows-based operating system, the driver nicm.sys will be loaded at system startup. This driver allows any user to open the device "\.nicm" and issue IOCTLs with a buffering mode of METHOD_NEITHER.

Due to insufficient input validation, user mode software can pass kernel addresses as arguments to the driver. By using specially constructed input, a malicious user can use functionality within the driver to patch kernel addresses and execute arbitrary code in kernel mode.

ANALYSIS

Exploitation of this vulnerability allows a local attacker to execute arbitrary code within the kernel. To exploit the vulnerability, the attacker must be able execute a specially crafted executable on the targeted computer.

DETECTION

iDefense has confirmed the existence of this vulnerability in nicm.sys, file version 3.0.0.4, as included with Novell's NetWare Client 4.91 SP4. Other versions may also be vulnerable.

WORKAROUND

iDefense is currently unaware of any workaround for this issue.

VENDOR RESPONSE

Novell Inc. has addressed this vulnerability by releasing a patch for the NetWare Client SP3. For more information visit the following URL.

http://download.novell.com/Download?buildid=4FmI89wOmg4~

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-5762 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

10/30/2007 Initial vendor notification
11/13/2007 Initial vendor response
01/09/2008 Coordinated public disclosure

CREDIT

This vulnerability was reported to iDefense by Stephen Fewer of Harmony Security (www.harmonysecurity.com)

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LEGAL NOTICES

Copyright © 2008 Verisign, Inc.

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