Microsoft Vulnerability Research Advisory MSVR12-001

Vulnerabilities in XnViewer Could Allow Remote Code Execution

Published: January 17, 2012

Version: 1.0

Overview

Executive Summary

Microsoft is providing notification of the discovery and remediation of two integer overflow vulnerabilities affecting XnViewer version 1.98.2 and earlier versions. Microsoft discovered and disclosed the vulnerabilities under coordinated vulnerability disclosure to the affected vendor, XnView. XnView has remediated the vulnerabilities in their software.

Both integer overflow vulnerabilities exist in the way that XnViewer handles certain PSD record types. Both vulnerabilities could allow remote code execution if a user opens a specially crafted file with an affected version of XnViewer. An attacker who successfully exploited either of these vulnerabilities could run arbitrary code in the security context of the logged-on user. If a user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Microsoft Vulnerability Research reported these issues to and coordinated with XnView to ensure remediation. The vulnerabilities have been assigned the entries CVE-2012-0684 and CVE-2012-0685 in the Common Vulnerabilities and Exposures list. For more information about updates from XnView, please see the XnViewer download page.

Mitigating Factors

• The vulnerabilities cannot be exploited automatically through email. For an attack to be successful, a user must open an attachment that is sent in an email message.
• In a web-based attack scenario, an attacker could host a website that contains a specially crafted file that is used to exploit either of these vulnerabilities. In addition, compromised websites and websites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit either of these vulnerabilities. In all cases, however, an attacker would have no way to force users to visit these websites. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes users to the attacker’s website, and then convince them to open the specially crafted file.
• An attacker who successfully exploited either of these vulnerabilities could gain the same user rights as the logged-on user. 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.

Advisory Details

Purpose and Recommendation

Purpose of Advisory: To notify users of a vulnerability and its remediation.

Advisory Status: Advisory published.

Recommendation: Review the Suggested Actions section and configure as appropriate.

Issue References

For more information about this issue, see the following references:

Affected and Non-Affected Software

This advisory discusses the following software:

Frequently Asked Questions

What is the scope of this advisory?
This advisory is part of a coordinated release with affected vendors to inform customers of security issues that may affect their systems.

Is this a security vulnerability that requires Microsoft to issue a security update?
No. These vulnerabilities have been fixed via an update from the affected third-party vendors. The update remediates the software listed in the table, Affected Software.

What is the scope of the vulnerabilities?
These are remote code execution vulnerabilities. An attacker who successfully exploited either of these vulnerabilities could run arbitrary code in the security context of the logged-on user. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

What causes the vulnerabilities?
Both vulnerabilities exist when XnViewer does not properly handle certain PSD record types causing an integer overflow.

What might an attacker use this vulnerability to do?
An attacker who successfully exploited either of these vulnerabilities could run arbitrary code in the security context of the logged-on user. If the user is logged on with administrative user rights, an attacker who successfully exploited either of these vulnerabilities could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. 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.

How could an attacker exploit the vulnerability?
An attacker could exploit either of these vulnerabilities by tricking a user into opening a specially crafted file with an affected version of XnViewer. Typically these specially crafted files are delivered via social engineering techniques in email, instant messaging, or via download links on websites. These vulnerabilities cannot be exploited without user interaction.

Suggested Actions

Download and use the latest version of XnViewer.

Other Information

Acknowledgments

Microsoft thanks the following:

• Justin Kim and Jeong Wook Oh of Microsoft Malware Protection Center (MMPC) for working with MSVR to have these vulnerabilities reported and remediated

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

• V1.0 (January 17, 2012): Advisory published.

Built at 2014-04-18T13:49:36Z-07:00