Beware Malicious Publisher and Visio Documents

Summary:

• These vulnerabilities affect: All current version of Microsoft Office Publisher and Visio
• How an attacker exploits them: By enticing you to open maliciously crafted Publisher or Visio documents
• Impact: An attacker can execute code, potentially gaining complete control of your computer
• What to do: Install the appropriate Office Publisher and Visio patches immediately, or let Microsoft’s Automatic Update do it for you.

Exposure:

Today, Microsoft released two security bulletins describing three vulnerabilities found in Microsoft Office Publisher and Microsoft Visio; two applications that belong to Microsoft’s Office line of products.

While the vulnerabilities differ technically, and affect two different applications from the Office line, they share the same general scope and impact. By enticing one of your users into downloading and opening a maliciously crafted document, an attacker can exploit any of these vulnerabilities to execute code on a victim’s computer, inheriting that user’s level of privileges and permissions. If your user has local administrative privileges, the attacker gains full control of the user’s machine.

The notable difference between these flaws lies in which document types can trigger the flaws. According to Microsoft, the vulnerable document types include Publisher documents (.PUB) and Visio files (.VSD, .VST, .VSS, .VDX).

If you’d like to learn more about each individual flaw, drill into the “Vulnerability Details” section of the security bulletins listed below:

• MS10-023: Microsoft Office Publisher Code Execution Vulnerability, rated Important
• MS10-028: MicrosoftVisio Code Execution Vulnerabilities, rated Important

Solution Path

Microsoft has released patches for Publisher and Visio to correct all of these vulnerabilities. You should download, test, and deploy the appropriate patches throughout your network immediately, or let the Microsoft Automatic Update feature do it for you.

MS10-023:

• Office Publisher 2002
• Office Publisher 2003
• Office Publisher 2007

MS10-028:

• Office Visio 2002
• Office Visio 2003
• Office Visio 2007

For All WatchGuard Users:

While you can configure certain WatchGuard Firebox models to block Microsoft Publisher and Visio documents, some organizations need to allow them in order to conduct business. Therefore, these patches are your best recourse.

If you want to block Office documents, follow the links below for video instructions on using your Firebox proxy’s content blocking features by file extensions. Some of the file extensions you’d want to block include, .PUB, VSD, and .VDX. Keep in mind, blocking files by extension blocks both malicious and legitimate documents.

• 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 Office updates to fix these vulnerabilities.

References:

• MS Security Bulletin MS10-023
• MS Security Bulletin MS10-028