Microsoft Internet Explorer modal dialog box race condition

Date Discovered: 2006. április 26.
Date Published: 2006. május 3.
Last Updated: 2006. május 3.

Threat Assessment
Overall Risk: Medium
Impact:          Medium
Popularity:    High
Simplicity:     Very Low

Vulnerability Description
Vulnerability ID:          34090
Discovered By:            Matthew Murphy
Exploitable Locally:    No
Exploitable Remotely: Yes
Impact:                       Remote attackers can execute arbitrary code.
Root Cause:                Software Vulnerability

Microsoft Internet Explorer contains a vulnerability that can allow an attacker to execute arbitrary code. The vulnerability is due to a timing issue in the way modal dialog boxes are handled. Attackers can exploit the vulnerability to trick a user into permitting the execution of malicious code.

Recommendations
For: Microsoft Internet Explorer 5.5 SP2 x86 32, Microsoft Internet Explorer 6 SP1 x86 32, Microsoft Internet Explorer 6 XP SP2 x86 32, Microsoft Internet Explorer 6.0 for Windows Server 2003 x86 32, Microsoft Internet Explorer 6.0 SP1 for Windows Server 2003 x86 32

If the vendor supplied patch is not available or installation is not feasible, the following steps can be used to limit exposure.

1. Implement a firewall
2. Install Anti-virus and Spyware detection software and ensure definitions are kept current
3. Check for software updates on a regular basis; if updates are available apply them as soon as possible
4. Use vigilance when opening HTML formatted emails, following links embedded in emails or links from an unknown source
5. Use a non-administrative privileged account for general tasks
6. Do not open files from untrusted or unconfirmed sources

Affected Technologies
Microsoft: Microsoft Internet Explorer 5.5 SP2 x86 32
Microsoft: Microsoft Internet Explorer 6 SP1 x86 32
Microsoft: Microsoft Internet Explorer 6 XP SP2 x86 32
Microsoft: Microsoft Internet Explorer 6.0 for Windows Server 2003 x86 32
Microsoft: Microsoft Internet Explorer 6.0 SP1 for Windows Server 2003 x86 32

References
Mitre CVE: CVE-2006-2094

More information on CA Vulnerability Information Center:
http://www3.ca.com/securityadvisor/vulninfo/vuln.aspx?id=34090

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