Archive | November, 2010

Huge OS X Update Closes 134 Security Holes

Summary:

  • These vulnerabilities affect: All current versions of OS X 10.5.x (Leopard) and OS X 10.6.x (Snow Leopard)
  • How an attacker exploits them: Multiple vectors of attack, including enticing your users into downloading and viewing various documents or images
  • Impact: Various results; in the worst case, an attacker executes code on your user’s computer
  • What to do: OS X administrators should download, test and install OS X 10.6.5 or Security Update 2010-007 as soon as possible, or let Apple’s Software updater do it for you.

Exposure:

Today, Apple released a security update to fix vulnerabilities in all current versions of OS X. The update fixes 134 (number based on CVE-IDs) security issues in 34 components that ship as part of OS X or OS X Server, including Quicktime, ImageIO, and Apache. Some of the fixed vulnerabilities include:

  • Multiple ImageIO Buffer Overflow Vulnerability. ImageIO is one of the components that helps OS X handle various image file types. Unfortunately, it also suffers from various security vulnerabilities involving the way it handles certain types of image files (such as a buffer overflow vulnerability). Though these vulnerabilities differ technically, they generally share the same scope and impact. If an attacker can get a victim to view a specially crafted image file (perhaps hosted on a malicious website), he could exploit this flaw to either crash an application or to execute attack code on the victim’s computer. By default, the attacker would only execute code with that user’s privileges. The affected image types include, PNG, TIFF, and PSD.
  • Various ATS Vulnerabilities. The Apple Type Service (ATS) helps OS X machines handle fonts. ATS suffers from various memory related vulnerabilities having to do with the way it handles certain types of embedded fonts. By tricking one of your users into downloading and viewing a malicious document containing a specially crafted font, an attacker can exploit this flaw to execute code on that user’s computer. By default, the attacker would only execute code with that user’s privileges.
  • Nine Quicktime Vulnerabilities. Quicktime is the popular video and media player that ships with OS X (and iTunes). Quicktime suffers from nine security issues (number based on CVE-IDs) involving how it handles certain image and video files. While the vulnerabilities differ technically, they share the same basic scope and impact. If an attacker can trick one of your users into viewing a maliciously crafted image or video in QuickTime, he could exploit any of these flaws to execute code on that user’s computer, with that user’s privileges.

Apple’s alert also describes many other code execution vulnerabilities, as well as some Denial of Service (DoS) flaws, cross-site scripting (XSS) vulnerabilities, information disclosure flaws, and other security issues. Components patched by this security update include:

AFP Server Apache mod_perl
Apache AppKit
ATS CFNetwork
CoreGraphics CoreText
CUPS Directory Service
diskdev_cmds Disk Images
Flash Player plugin gzip
Image Capture ImageIO
Image RAW Kernel
MySQL neon
Networking OpenLDAP
OpenSSL Password Server
PHP Printing
python QuickLook
QuickTime Safari RSS
Time Machine Wiki Server
X11 xar

Please refer to Apple’s OS X 10.5.x and 10.6.x alert for more details.

Solution Path:

Apple has released OS X Security Update 2010-007 and OS X 10.6.5 to fix these security issues. OS X administrators should download, test, and deploy the corresponding update as soon as they can.

Note: If you have trouble figuring out which of these patches corresponds to your version of OS X, we recommend that you let OS X’s Software Update utility pick the correct updates for you automatically.

For All Users:

These flaws enable many diverse exploitation methods. Some of the exploits are local, meaning that your perimeter firewall never encounters the attack (unless you use firewalls internally between departments). Installing these updates, therefore, is the most secure course of action.

Status:

Apple has released updates to fix these flaws.

References:

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

 

Two Office Security Bulletins Fix Seven Vulnerabilities

Summary:

  • These vulnerabilities affect: Most current versions of Microsoft Office, and the components that ship with it
  • How an attacker exploits it: Typically by enticing one of your users to open a malicious Office document
  • Impact: In the worst case, an attacker executes code on your user’s computer, gaining complete control of it
  • What to do: Install Microsoft Office updates as soon as possible, or let Microsoft’s automatic update do it for you

Exposure:

As part of today’s Patch Day, Microsoft released two security bulletins describing seven vulnerabilities found in components that ship with most current versions of Microsoft Office for Windows and Mac.

The vulnerabilities affect different versions of Office to varying degrees. Though the seven vulnerabilities differ technically, and affect different Office components, they share the same general scope and impact. By enticing one of your users into downloading and opening a maliciously crafted Office document, an attacker can exploit any of these vulnerabilities to execute code on a victim’s computer, usually 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.

According to Microsoft’s bulletins, an attacker can exploit these flaws using many different types of Office documents. In one bulletin, Microsoft specifically states PowerPoint documents are vulnerable. However, they also mention any “Office files” in their other alert. Therefore, we recommend you beware of all unexpected Office documents.

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

  • MS10-087: Five Office Code Execution Vulnerabilities, rated Critical
  • MS10-088: Two PowerPoint Code Execution Vulnerabilities, rated Important

Solution Path

Microsoft has released patches for Office 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.

MS10-087:

Note: Office 2004 and 2008 for Mac are also vulnerable to these flaws, however, Microsoft has not created a updates for these Mac versions yet.

MS10-088:

PowerPoint update for:

Note: Office 2004 for Mac is vulnerable to these flaws, however, Microsoft has not created an update for this Mac version yet.

For All WatchGuard Users:

While you can configure certain WatchGuard Firebox models to block Microsoft Office 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, .DOC, .XLS, .PPT, and many more (including the newer Office extensions that end with “X”). Keep in mind, blocking files by extension blocks both malicious and legitimate documents.

Status:

Microsoft has released Office updates to fix these vulnerabilities.

References:

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

 


%d bloggers like this: