Evil Visio 2003 Documents Could Install Malware

Severity: Medium

12 July, 2011

Summary:

• This vulnerability affects: Visio 2003, only
• How an attacker exploits it: By enticing one of your users into opening a maliciously crafted Visio document
• Impact: An attacker can execute code, potentially gaining complete control of your users’ computers
• What to do: Deploy the Visio 2003 patch as soon as possible, or let Windows Update do it for you

Exposure:

Microsoft Visio is a very popular diagramming application, which many administrators use to create network diagrams. It also ships with some Office packages.

In a security bulletin released today, Microsoft describes a security vulnerability that only affects Visio 2003. Specifically, Visio 2003 suffers from an insecure Dynamic Link Library (DLL) loading vulnerability, sometimes referred to as a binary planting flaw. We first described this class of flaw in a September Wire post, which describes this Microsoft security advisory. If an attacker can entice one of your users into opening a Visio related filw (such as .vsd, .vdx, .vst, or .vtx) file from the same location as a specially crafted DLL, he could exploit this flaw to execute code on that user’s computer with full system privileges, thus gaining complete control of the computer.

Solution Path:

Microsoft has released a Visio 2003 patch to fix this flaw. You should download, and deploy the patch as soon as possible, or let Windows Update do it for you.

For All WatchGuard Users:

If the practice fits your business environment, you can use the HTTP, SMTP, and/or POP3 proxies to block Visio documents by extension (such as .vsd, .vdx, .vst, or .vtx). However, doing so blocks both malicious and legitimate file.

If you would like to use our proxies to block Visio documents, follow the links below for instructions:

• XTM Appliance with WSM 11.x
• How do I block files with the FTP proxy?
• How do I block files with the HTTP proxy?
• How do I block files with the POP3 proxy?
• How do I block files with the SMTP Proxy?

• Firebox X Edge running 10.x
  • How do I block files with the FTP proxy?
  • How do I block files with the HTTP proxy?
  • How do I block files with the POP3 proxy?
  • How do I block files with the SMTP proxy

• Firebox X Core and X Peak running Fireware 10.x
  • How do I block files with the FTP proxy?
  • How do I block files with the HTTP proxy?
  • How do I block files with the POP3 proxy?
  • How do I block files with the SMTP proxy?

Status:

Microsoft has released a fix.

References:

• MS Security Bulletin MS11-055

This alert was researched and written by Corey Nachreiner, CISSP.

---

What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

More alerts and articles: Log into the LiveSecurity Archive.