Monday, August 9, 2010

Microsoft out-of-band security update to .LNK Issue

Microsoft is releasing an out-of-band security update to address the .LNK vulnerability described in Microsoft Security Advisory 2286198. MS10-046 addresses one vulnerability in Windows, which has a maximum severity rating of Critical and an Exploitability Index rating of 1. The security vulnerability affects all supported editions of Windows, including Windows XP, Windows Vista, Windows 7, Windows Server 2008, and Windows Server 2008 R2.

It is recommended that customers deploy the update as soon as possible to help protect their computers from criminal attacks. The security update protects against attempts to exploit the vulnerability by several malware families

This alert is to provide you with an overview of the new security bulletin released (out-of-band) on August 2, 2010.


Microsoft is releasing one new security bulletin (out-of-band) for newly discovered vulnerabilities:

Bulletin Identifier

Microsoft Security Bulletin MS10-046

Bulletin Title

Vulnerability in Windows Shell Could Allow Remote Code Execution (2286198)

Executive Summary

This security update resolves a publicly disclosed vulnerability in Windows Shell. The vulnerability could allow remote code execution if the icon of a specially crafted shortcut is displayed. The security update addresses the vulnerability by correcting validation of shortcut icon references. This security update also addresses the vulnerability first described in Microsoft Security Advisory 2286198.

Affected Software

This security update is rated Critical for all supported editions of Windows.

CVE, Exploitability Index Rating

CVE-2010-2568: Shortcut Icon Loading Vulnerability (EI = 1)

Attack Vectors

  • A maliciously crafted shortcut file.
  • Common delivery mechanisms: a maliciously crafted Web page, an e-mail attachment, an instant message, a peer-to-peer file share, a network share, or a USB thumb drive.

Mitigating Factors

  • Users would have to be persuaded to visit a malicious Web site.
  • Exploitation only gains the same user rights as the logged-on account. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.
  • Blocking outbound SMB connections on the perimeter firewall reduces the risk of remote exploitation using file shares.

Restart Requirement

The update will require a restart.

Bulletins Replaced by This Update


Publicly Disclosed?

Yes—this vulnerability was publicly disclosed prior to release. More information is contained in Microsoft Security Advisory 2286198.
Yes—this vulnerability has been exploited in the wild at release.

Full Details