• Articles
    • Editorial Articles
    • Research Articles
    • WatchGuard Articles
  • The 443 Podcast
  • Threat Landscape
  • About
    • About Us
    • Contact Us
    • Contribute to Secplicity

Secplicity - Security Simplified

Powered by WatchGuard Technologies

VBA Vulnerability Makes Office Documents Dangerous

May 11, 2010 By The Editor

Summary:

  • This vulnerability affects: Microsoft Visual Basic for Applications (VBA), which ships with all current versions of Office
  • How an attacker exploits it: By tricking one of your users into opening a malicious Office document
  • Impact: An attacker can potentially gain complete control of your windows computers (depending on the privileges of the user)
  • What to do: Download, test, and install Microsoft’s update as soon as possible, or let Windows Automatic Update do it for you

Exposure:

According to Microsoft, Visual Basic for Applications (VBA) is “a development technology for developing client desktop packaged applications and integrating them with existing data and systems.” In more understandable terms, it’s a programming language that allows developers to make customized applications based on the Office applications. All current versions of Office ship with VBA, and the Office applications make use of it to perform certain functions.

According to this Microsoft security bulletin, VBA suffers from a memory corruption vulnerability having to do with the way it searches for ActiveX controls in a document that supports VBA. Without getting too deep into the technical details, if an attacker can lure one of your users into downloading a specially crafted Office document that supports VBA, he can exploit this flaw to execute code on that user’s computer, with that user’s privileges. If the user has local administrator privileges, that attacker gains full control of the PC. An attacker can trigger this flaw using just about any Office document, including Word, PowerPoint, and Excel documents.

Solution Path:

Microsoft has released patches to fix these vulnerabilities. You should download, test, and deploy the appropriate Office and VBA patches as soon as possible, or let Windows Automatic Update do it for you.

  • Office XP
  • Office 2003
  • 2007 Microsoft Office System
  • Microsoft Visual Basic for Applications

For All WatchGuard Users:

You can configure certain WatchGuard Firebox models to block Microsoft Office documents, such as Word, PowerPoint, and Excel documents. However, most organizations need to allow Office documents in order to conduct business. Therefore, Microsoft patches are your best recourse.

Nonetheless, if you do 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:

  • .doc
  • .docx
  • .ppt
  • .pptx
  • .xls
  • .xlsx

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 patches to fix these vulnerabilities.

References:

  • MS Security Bulletin MS10-031

Share This:

Related

Filed Under: Security Bytes Tagged With: Microsoft, vba, visual basic

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

The 443 Podcast

A weekly podcast featuring the leading white-hat hackers and security researchers. Listen Now
the 443 podcast

Threat Landscape

Filter and view Firebox Feed data by type of attack, region, country, and date range. View Now
threat landscape

Top Posts

  • Cybersecurity News: Free Cybersecurity Training, TrickBot Group Exposed, Major GoDaddy Breach, and Russia to Legalize cybercrime?!
  • US National Cybersecurity Strategy
  • 3CX Supply Chain Attack
  • Here Come The Regulations

Email Newsletter

Sign up to get the latest security news and threat analysis delivered straight to your inbox

By signing up you agree to our Privacy Policy.


The views and opinions expressed on this website are those of the authors and do not necessarily reflect the policy or position of WatchGuard Technologies.

Stay in Touch

Recent Posts

  • 3CX Supply Chain Attack
  • The NSA’s Guidance on Securing Authentication
  • Cybersecurity News: LastPass Incident Revealed, White House Issues Cybersecurity Strategy, FBI Purchases Leaked USHOR PII Data, and a Slew of Other Breaches
  • An Update on Section 230
  • Here Come The Regulations
View All

Search

Archives

Copyright © 2023 WatchGuard Technologies · Cookie Policy · Privacy Policy · Terms of Use