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Update Protection against Microsoft Excel ExternSheet Record Indexing Memory Corruption Vulnerability (MS09-021)

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Check Point Reference: CPAI-2009-142
Date Published:
Severity:
Last Updated:
Source: Microsoft Security Bulletin MS09-021
Industry Reference(s): CVE-2009-0558
Protection Provided by: Security Gateway
  • R70
IPS-1
  • IPS-1
  • IPS-1 NGX R65
Who is Vulnerable?
Microsoft Office Excel 2000 SP3
Microsoft Office for Mac 2004
Microsoft Office for Mac 2008
Vulnerability Description
A remote code execution vulnerability has been identified in the Microsoft Excel. Microsoft Excel is a popular spreadsheet application. A remote attacker could exploit this issue via a malformed Excel file. Successful exploitation of this vulnerability may allow execution of arbitrary code on a target system.
Update/Patch Available
Apply patches:
Microsoft Security Bulletin MS09-021
Vulnerability Details
The vulnerability is due to a memory corruption error when Microsoft Excel reads a value from a specially crafted Excel file and then uses it as an index into an array without validation. A remote attacker could trigger this flaw by convincing a victim to open a malformed Excel spreadsheet file. Successful exploitation of this issue may allow the attacker to take complete control of an affected system.

Protection Overview
This protection will detect and block the transferring of malformed Excel files over HTTP.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, Protection tab and select the version of your choice.

To configure the defense, select your product from the list below and follow the related protection steps.

Security Gateway R70

How Can I Protect My Network?
1. In the IPS tab, click Protections > By Protocol > Application Intelligence > Content Protection.
2. In the right pane, double-click the Microsoft Excel ExternSheet Record Indexing Memory Corruption (MS09-021) protection.
3. In the Protection Details window, click on Edit. Choose the protection's Action (Override IPS Policy with: Prevent/Detect), and apply Additional Settings.
4. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: Content Protection Violation
Attack Information: Microsoft Excel ExternSheet record indexing memory corruption (MS09-021)

IPS-1 & IPS-1 NGX R65

How Can I Protect My Network?
1. In the IPS-1 Policy Manager, click on the Protection tab.
2. In the Protection tree, click Application Intelligence > Badfiles, and select the Microsoft Office Parser protection group.
3. Click CVE-2009-0558 Microsoft Excel Array Indexing Memory Corruption (MS09-021) (IPS-1 NGX R65 only).
4. In the configuration pane, under Settings, check Active.
5. Click on Install Policy.

How Do I Know if My Network is Under Attack?
Upon attack, the following entry will be logged:

Alert Name: Vulnerability in MS-Office file
Description: CVE-2009-0558 Microsoft Excel Array Indexing Memory Corruption (MS09-021)