UniBrows may be a solution for those companies, considering that newer versions of Internet Explorer offer improved web compatibilities and security as well as faster speeds.

The browser plugin works similar to IETab add-ons that are available for Firefox and Google Chrome, with the difference that it adds Internet Explorer 6 compatibility to Internet Explorer 8.

UniBrows can be configured with rules. It is for instance possible to configure urls to open as if they were opened in Internet Explorer 6. That’s great for companies who do not want to update their applications or operating systems because of compatibility issues.

UniBrows is an IE8 add-on that allows your business to finally make the move to modern technologies. Sign up for the Beta program today to enjoy:

• Application Compatibility with your existing IE6 applications
• Easy deployment and management unlike virtualization solutions
• Simple Migration without changing a single line of code
• Greater security and ease of use for the end user

The plugin “provides full IE6 functionality and behaviors, including ActiveX controls support, rendering, and JavaScript functionality”. The plugin is currently available only to beta testers, but anyone can sign up to test it before it is released.

The update for Internet Explorer will be provided through Windows Updates or from the usual Microsoft sites where updates can be downloaded manually. The reason for the out of band update is Microsoft’s monitoring of the vulnerability which seemed to have uncovered an increased exploitation of the security vulnerability.

The update for Internet Explorer is cumulative as it contains nine additional vulnerability fixes that all were supposed to be released on Microsoft’s monthly patch Tuesday on April 13.

The main impact of the vulnerability is remote code execution:

The vulnerability exists due to an invalid pointer reference being used within Internet Explorer. It is possible under certain conditions for the invalid pointer to be accessed after an object is deleted. In a specially-crafted attack, in attempting to access a freed object, Internet Explorer can be caused to allow remote code execution.

Admins and users who still run systems with Internet Explorer 6 or 7 are encouraged to update their systems as soon as the update is released by Microsoft to protect the system from being successfully compromised.

The vulnerability only affected Internet Explorer 6 and Internet Explorer 7; Anyone updating their web browser to the latest official version of Internet Explorer would protect the computer system from the security vulnerability.

But not everyone was able to update. Especially users in corporate environments have still to cope with outdated versions of Internet Explorer.

Microsoft now has released a so called Fix It solution to patch the vulnerability so that it cannot be exploited anymore. A Fix It solution is basically a small program that can be executed right from the web browser to fix problems on the operating system.

Actually, there are two fix it solutions for the same vulnerability and it is enough to use one of them to protect the PC from the Internet Explorer vulnerability.

• Fix it solution for peer factory in iepeers.dll We have created an application compatibility database that will disable peer factory in the iepeers.dll binary for supported versions of Internet Explorer on Windows XP and Windows Server 2003.
  To install this application compatibility database, click the Fix it button in the “Fix it solution for peer factory in iepeers.dll” section.
• Fix it solution for Data Execution Prevention We have created an application compatibility database that will enable Data Execution Prevention (DEP) for all versions of Internet Explorer that support DEP. You do not need this database if you are using Internet Explorer 8 on Windows XP Service Pack 3 (SP3) or on Windows Vista SP1 or later versions. This is because Internet Explorer 8 opts-in to DEP by default on these platforms.
  To install this application compatibility database, click the Fix it button in the “Fix it solution for Data Execution Prevention” section

The second Fix-It patch requires a computer system that supports DEP which means that it works on every Microsoft operating system from Windows XP on which obviously excludes Windows 2000. The processor also needs to support Hardware-enforced DEP

Both Fix It solutions can be executed or downloaded form this Microsoft Knowledgebase article.

The impact of the vulnerability is a remote code execution that can be triggered by an invalid pointer reference that can be the cause for the remote code execution.

Microsoft is aware of targeted attacks. It is therefor recommended to update Internet Explorer to the latest version or ensure that Protected Mode in Internet Explorer is enabled.

Possible attack vectors are manipulated websites that are used to exploit the security vulnerability either directly or by third party code that is being displayed on the website or by attacking the email clients Microsoft Outlook or Windows Mail with HTML emails that exploit the vulnerability.

Interested users can visit the security advisory issued by Microsoft to get additional information about the security vulnerability.

Another possibility to protect the computer from the vulnerability would be to switch at least temporary to another Internet browser although this might not always be possible.

There are various options to test a website in different versions of Internet Explorer. Some, like IETester, make it possible to install multiple versions of Internet Explorer on the same computer system. Others, like Browsershots, are online tools that can test a website in various web browsers as well.

A third possibility is now offered by Microsoft directly in the form of virtual PC images. Internet Explorer 6, Internet Explorer 7 and Internet Explorer 8 are provided as virtual PC images. It is possible to download a virtual PC image for each web browser running under Windows XP or Internet Explorer 7 or Internet Explorer 8 images running under Windows Vista.

The Windows XP images have a size of around 600 Megabytes each while the Windows Vista images triple that size. The only limitation is an expiration date for the virtual PC images. The Windows XP images will expire in January 2010 while the Vista images will expire 120 days after their first execution. These expiration dates make the virtual PC images a less than favorable solution but its probably better than not testing the various editions of Internet Explorer at all.

Users who are interested in the virtual PC images can download them directly from the Microsoft website.

Not included are the browsing history or session cookies which is a bit unfortunate as it could mean to log into several of the websites again if they require that. The extension becomes available in the Tools menu of Internet Explorer after installation where the sessions can be stored or loaded.

The Internet Explorer sessions are stored in the program directory by default. The extension provides the option to store them at the Amazon S3 Service instead which costs $0.150 per GB but has the advantage that the sessions are available online and can therefor be loaded from any computer with Internet connection.

Another option would be to send the session per email or upload it manually to the Internet to access it from a second computer.

One interesting aspect of the session manager for Internet Explorer is the ability to manage the stored urls of each session. Single urls can be loaded in the browser. It is also possible to delete urls from the session.

IE Sessions supports Internet Explorer 6 or on Windows XP or Windows 2000. Windows Vista users should read the information posted on the website about Vista compatibility first before they install the extension.

The problem begins when the webmaster realizes that Microsoft has made it virtually impossible to install and use different versions of Internet Explorer on the same computer system. Unlike Firefox or Opera where it is possible to install different versions separately that option has been neglected in Internet Explorer.

A first step in the right direction was the IETester tool which emulated various Internet Explorer versions in one interface making it possible to view websites with different Internet Explorer versions.

The next step however is the Internet Explorer Collection. The collection comes with several Internet Explorer versions from Internet Explorer 1 to Internet Explorer 8 in one installation package. It does include the highly popular Internet Explorer 6 and Internet Explorer 7.

• Internet Explorer 1.0 (4.40.308)
• Internet Explorer 1.5 (0.1.0.10)
• Internet Explorer 2.01 (2.01.046)
• Internet Explorer 3.0 (3.0.1152)
• Internet Explorer 3.01 (3.01.2723)
• Internet Explorer 3.03 (3.03.2925)
• Internet Explorer 4.01 (4.72.3110.0)
• Internet Explorer 5.01 (5.00.3314.2100)
• Internet Explorer 5.5 (5.51.4807.2300)
• Internet Explorer 6.0 (6.00.2800.1106)
• Internet Explorer 6.0 (6.00.2900.2180)
• Internet Explorer 7.0 (7.00.5730.13)
• Internet Explorer 8.0 (8.00.6001.18702)

The best part is that you can pick the Internet Explorer versions that you want and install them on your system separately which in turn means that it is possible to test a website in each version of Internet Explorer independently.

After downloading Internet Explorer Collection the user is presented with several check boxes during installation which when selected install the specific version of Internet Explorer.

It does not make much sense to install the early versions, at least when website testing is the main consideration for installing the different versions. It could be nice for a nostalgic trip however or just for fun to see how fast (or not) those old versions were.

Each version of Internet Explorer that has been installed on the system because accessible through the Windows Start Menu. A click on the Internet Explorer icon will launch that version, it is even possible to launch and run several versions of Internet Explorer simultaneously.

The developer of Internet Explorer Collection is shy on words because there is virtually no information on his website about the technique that he uses to run the Internet Explorer versions on the same computer system.

Internet Explorer 7 Standalone (IE7 Standalone) comes in handy if you are still running Internet Explorer 6 on your system but want to install Internet Explorer 7 as well to be able to use both browsers on your system. It’s basically a script that downloads Internet Explorer 7 directly from Microsoft and installs it as a standalone application on your computer. This means that it does not mess with Internet Explorer 6 in any way and that it is possible to load either one of them.

This method does have some shortcomings though. Some features that require Registry keys that are still occupied by Internet Explorer 6 are broken and will not work in Internet Explorer 7 standalone. The developer is listing several features that seem to be broken although most do not explain the aspect that is not working.

This is a great way to run both Internet Explorer 6 and 7 on the same system. A quick test did not reveal any difficulties so far.