Criticism of Internet Explorer

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Internet Explorer is a web browser that is subjected to many criticisms. Most of the criticism concerns its security architecture and its degree of support of open standards.

Contents 1 Criticisms regarding security 1.1 Component Object Model 1.2 Patches 1.3 Spyware, adware and Windows XP SP2 2 Criticisms regarding support of open standards 2.1 XHTML 2.2 HTTP and MIME 2.3 CSS 2.4 JavaScript and DOM 2.5 PNG graphics 2.6 Plugin API 2.7 Workarounds 3 Other criticisms 3.1 Increased download size 3.2 Unclear error messages 3.3 Lack of development 2001-2005 3.4 Critism of Internet Explorer 7 4 Footnotes 5 See also 6 References 7 External links

[edit] Criticisms regarding security

Internet Explorer comes under heavy scrutiny from the computer security research community, in part due to its sheer ubiquity. Exploitation of Internet Explorer's security holes has earned IE the reputation as the least secure of the major web browsers.

As of January 2, 2007, security advisory site Secunia counted 18 unpatched security flaws for Internet Explorer 6, many more and older than for any other browser, even in each individual criticality-level, although some of these flaws only affect Internet Explorer when running on certain versions of Windows or when running in conjunction with certain other applications.^[1]

See computer security for more details about the importance of unpatched known flaws.

On June 23, 2004, an attacker using compromised Internet Information Services 5.0 Web servers on major corporate sites used two previously undiscovered security holes in Internet Explorer to insert spam-sending software on an unknown number of end-user computers.^[2] This malware became known as Download.ject and it caused users to infect their computers with a back door and key logger merely by viewing a web page. Infected sites included several financial sites.

Art Manion, a representative of the United States Computer Emergency Readiness Team (US-CERT) noted in a vulnerability report that the design of Internet Explorer 6 Service Pack 1 made it difficult to secure. He stated that:

“

There are a number of significant vulnerabilities in technologies relating to the IE domain/zone security model, local file system (Local Machine Zone) trust, the Dynamic HTML (DHTML) document object model (in particular, proprietary DHTML features), the HTML Help system, MIME type determination, the graphical user interface (GUI), and ActiveX. … IE is integrated into Windows to such an extent that vulnerabilities in IE frequently provide an attacker significant access to the operating system.[3]

”

Manion later clarified that most of these concerns were addressed in 2004 with the release of Windows XP Service Pack 2, and other browsers have now begun to suffer the same vulnerabilities he identified in the above CERT report.^[4]

Microsoft has addressed this problem in two distinct ways with Windows Vista: User Account Control, which forces a user to confirm any action that could affect the stability or security of the system even when logged in as an administrator, and "Protected-mode IE", which runs the web browser process with much lower permissions than the user.^[5]

Many security analysts attribute Internet Explorer's frequency of exploitation in part to its ubiquity, since its market dominance makes it the most obvious target. However, some critics argue that this is not the full story; the Apache HTTP Server, for example, had a much larger market share than Microsoft IIS, yet Apache has traditionally had fewer (and generally less serious) security vulnerabilities than IIS.^[6] In an October 2002 interview, Microsoft's Craig Mundie admitted that Microsoft's products were "less secure than they could have been" because it was "designing with features in mind rather than security."^[7] IIS 6 has changed this, however; Secunia has only two vulnerabilities listed for the first three years since its release,^[8] compared with 15 for Apache 2.0 in the same time period.^[9]

As a result of its many problems, some security experts, including Bruce Schneier, recommend that users stop using Internet Explorer for normal browsing, and switch to a different browser instead.^[10] Several notable technology columnists have suggested the same, including the Wall Street Journal's Walt Mossberg,^[11] and eWeek's Steven Vaughan-Nichols.^[12] On July 6, 2004, US-CERT released an exploit report in which the last of seven workarounds was to use a different browser, especially when visiting untrusted sites.^[13] In December 2004, Pennsylvania State University issued an alert to students and staff telling them to drop IE and use an alternative.^[14]

[edit] Component Object Model

A number of IE's security issues are related to components based on Component Object Model (COM).^{[citation needed]}

More recently, other experts have noted that the dangers of ActiveX have been overstated and there are safeguards in place. In an April 2005 eWeek opinions column, Larry Seltzer stated:

“

While there has been a striking lack of actual evidence that ActiveX is unsafe, there has been no shortage of baseless assertions and cheap shots against it. My favorite was the "Internet Exploder" incident in which Sun actually paid someone to write a malicious ActiveX control. The test system brought up all the warning dialogs about the program that you usually get and the Sun employee actually had the nerve to keep whacking on the enter key quickly so they would close as quickly as possible and didn't mention that there were any such warnings. Meanwhile, they also didn't mention that a signed Java applet could also perform dangerous privileged operations and would provide similar warnings. Most ActiveX criticism is simply uninformed, but this example was hypocritical and dishonest.[15]

”

Other browsers that use NPAPI as their extensibility mechanism are suffering the same problems.

The forthcoming Windows Defender monitors Browser Helper Objects in Internet Explorer on Windows XP, Windows Server 2003, and Windows Vista and will warn the user before a new BHO is installed.

[edit] Patches

Another common criticism related to the security of Internet Explorer is the speed at which fixes are released after discovery of the problems, and that in some circumstances, the problems were not always completely fixed. For example, after Microsoft released patches to close holes in its Windows NT line of operating systems on February 2, 2004, 200 days after their initial report, Marc Maifrett, Chief Hacking Officer of eEye Digital Security, is quoted in a cNet article as saying:

“

If it really took them that long technically to make (and test) the fix, then they have other problems. That's not a way to run a software company.[16]

”

The same article quoted @stake's Chris Wysopal, vice president of research and development as saying:

“

Whatever time frame it takes to fix something, you could always argue that it could have been made somewhat shorter. It is definitely in the multimonth category because of how many versions of the operating system and the big applications that they had to test.

”

The Register criticized Maifrett for publicizing a security hole leading to the creation of the Code Red worm, arguing that:

“

had they not made such a grand public fuss over their .ida hole discovery and their SecureIIS product's ability to defeat it, it's a safe bet that Code Red would not have infected thousands of systems. … When we speak in favor of full disclosure, we're talking about something more narrowly targeted than eEye's usual media blitz whenever they discover a hole that their products can fix.[17]

”

Microsoft attributes the perceived delays to rigorous testing. The testing matrix for Internet Explorer demonstrates the complexity and thoroughness of corporate testing procedures. A posting to the Internet Explorer team blog on August 17, 2004 explained that there are, at minimum, 234 distinct releases of Internet Explorer that Microsoft supports (covering more than two dozen languages, and several different revisions of the operating system and browser level for each language), and that every combination is tested before a patch is released.^[18]

[edit] Spyware, adware and Windows XP SP2

Spyware and adware, like other malware, generally target Windows / Internet Explorer based systems. Older spyware attacks based on ActiveX have largely been mitigated by the security improvements in Windows XP SP2, but newer attacks against Internet Explorer allow the installation of spyware on SP2.

[edit] Criticisms regarding support of open standards

During the browser wars of the late 1990s, modifications of Internet Explorer and Netscape Navigator were focused on the addition of non-standard features.

Although each version of IE has improved standards support, including the introduction of a "standards-compliant mode" in version 6, the core standards that are used to build web pages (HTML and CSS) are sometimes implemented in an incomplete and incorrect fashion. For example, there is no support for the <abbr> element which is part of the HTML 4.01 standard, and there are bugs in the implementation of float-margins for the CSS1 standard.

Because of its market dominance, some web developers only test their websites with Internet Explorer. Some developers also use non-standard extensions offered by Internet Explorer. This can cause pages to be rendered incorrectly in other browsers. In the worst case, it could block the users of other browsers from accessing the sites created by such developers.

[edit] XHTML

Internet Explorer does not support native XHTML (the successor to the standard document markup language HTML), and when encountering a document being served with XHTML's MIME type (application/xhtml+xml), a file download prompt will be presented to the user.

Workarounds exist which instruct Internet Explorer to process XHTML documents as HTML.^{[citation needed]}

[edit] HTTP and MIME

Internet Explorer does not obey some MIME types specified in the MIME Content-Type header. ^[19][20]

Internet Explorer does not fully support HTTP/1.1 content negotiation, because the browser does not specify, in its requests, what character encodings it can accept. Content negotiation is a technique whereby an HTTP server uses the browser's—ultimately, the user's—preferences for media (MIME) type, languages, character encoding, and transfer encoding (for example, compression) in order to determine the best representation of a resource to send to a user agent, when multiple representations are available. An example would be the negotiation of image format (such as SVG, PNG, or GIF), and document format (WML, XHTML, or HTML, for instance).

[edit] CSS

While Internet Explorer – especially versions prior to 7.0 – recognizes most of the CSS Level 1 features, as well as parts of CSS2, it misinterprets some of them, resulting in inconsistent rendering behaviour. A number of "CSS hacks" were created to work around the various flaws in Internet Explorer's incorrect CSS parsing. While Internet Explorer 7 does fix some of the flaws with rendering, and adds support for CSS 2 features such as selectors, its support for the CSS 2 specification remains unfinished. Notable examples of improper support for CSS include:^[21]

• failure to interpret the W3C "Box" model
• inconsistent rendering of floating <DIV> layers
• "min-width" and "max-width" issues (also "min-height" and "max-height")
• little support for pseudo-classes such as :hover and :active
• inconsistent interpretation of CSS hierarchy
• misinterpretation of block element attributes, including:
  • position (fixed|absolute|relatve|static)
  • display (block|inline|table)

[edit] JavaScript and DOM

Microsoft has implemented Netscape's original JavaScript specification to create a scripting language called JScript, which is the default scripting language interpreted in Internet Explorer. Like Netscape's JavaScript implementation, JScript supports the full specification of ECMAScript.

What is different is the Document Object Model (DOM) bound with JScript. While all browsers have their own implementation of DOM Level 0 (vendor-specific), Internet Explorer implemented only some of the W3C recommended DOM Levels (1, 2 and 3). In addition, before DOM Level 2 was finalized, IE implemented some proprietary extensions to DOM which are similar, but not identical, to those in DOM Level 2. As the corresponding (finalized) DOM Level 2 objects and methods are not implemented in Internet Explorer, problems arise when trying to write scripts that work on any browser. Web developers often need to write extra code so that the scripts will work on both Internet Explorer and on browsers that correctly implement the W3C standards. This duplication increases development effort, results in code bloat, and makes code maintenance harder.

At least one error in Internet Explorer's implementation of the DOM allows the browser to unexpectedly crash. Entering the following 39-byte line of code into the address bar closes all instances of Internet Explorer:^[22]

javascript:for(x in document.write)f(x)

Furthermore, this code can easily be run by a malicious website unless Javascript is disabled, which few novice users can do.

[edit] PNG graphics

The lack of support for PNG alpha channel in versions prior to IE 7 has resulted in a reduced usage of the PNG image format on web pages. Alpha channel is a feature that, although being an optional part of the specification, distinguishes PNG from other formats like GIF or JPEG. In Internet Explorer, the transparent part of the image will be displayed as gray, white or other colors, depending on the image editor in which the PNG image was created. Microsoft documented a workaround on its support website ^[1], and the IE developers are aware of the missing functionality, as evidenced by a posting on IE developer Dave Massey's weblog ^[2]. This issue is fixed in Internet Explorer 7.

[edit] Plugin API

It did for a time support Netscape's NPAPI version 4. Plugins that functioned in the Netscape browser also functioned in Internet Explorer, but the support was dropped in version 5.5 SP2 in favor of Microsoft's own ActiveX technology.

[edit] Workarounds

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To get around these problems, many web designers build websites compliant to W3C standards, and then implement workarounds or hacks to account for Internet Explorer's rendering inadequacies, or to hide advanced website features from IE. The CSS hacks are often very complicated, as they need to deal with different versions of IE on different platforms (mostly Windows and Mac). The hacks utilize not just Internet Explorer-specific features, but also some rendering-engine bugs that are well known. Some of the more common hacks:

• Exploiting the "Star HTML selector" bug
• Exploiting the underscore hack
• Using CSS2 selectors that IE doesn't recognize
• Using JScript/VBScript and the IE CSS behavior
• Using the IE CSS filters
• Using the IE conditional comments

One of the most popular IE hack collections is known as IE7 ^[3], written by Dean Edwards. It is an attempt to make Internet Explorer more compliant when it comes to web standards. In addition to the support of some CSS2 selectors, it also fixes some of the IE bugs. However, as many client-side scripts need to be loaded and run before displaying the page properly, there is a considerable amount of loading time needed for every single page.

With the release of Internet Explorer 7, Microsoft addressed many shortcomings of previous versions, including a notable improvement of IE's support for the CSS2.1 standard. Some might find it ironic that the browser's new, improved CSS engine was so confounded by the hacks commonly utilized to mitigate deficiencies of its predecessors that Microsoft urged developers to remove CSS hacks in an article posted on its IEBlog^[4]. In order to support IE7 without compromising compatibility with previous versions, many web designers employ conditional comments.

[edit] Other criticisms

[edit] Increased download size

Over the versions, the download size of Internet Explorer has increased significantly. As of Internet Explorer 6 Service Pack 1 (including Outlook Express), the total download size for a typical installation was approximately 25 megabytes. The size varied between 11 (minimal install) and 75 MB (full install). This was much larger than that of some Internet suites, for example (based on Windows installer) Opera 8.0 (3.6MB), and Mozilla Suite 1.7.8 (11MB). Furthermore, installation of IE6 required users to be online, as a standalone installer was not released.

[edit] Unclear error messages

Internet Explorer also obfuscates error messages. "Page could not be displayed" is produced in many situations, and may indicate an HTTP 404 error, a DNS lookup failure, TCP error, SSL problem and probably many more. Although the actual problem is described in small type at the bottom, the prominence of "Page could not be displayed" means that it is typically the only text that will be reported to webmasters, leaving unsure what the problem was and unclear whether or not they need to take corrective action. This problem is exacerbated by the fact that Microsoft's IIS Web server software uses very similar error pages for server-side errors as well, introducing yet another type of error which, to the user, looks identical to all the rest. Error messages in Internet Explorer 7 have, however, been improved to be more informative and to offer more support to help the user identify and fix any possible problems that may be causing the error to be displayed.

[edit] Lack of development 2001-2005

The release of Windows XP Service Pack 2 in August 2004 was the only time Microsoft released any significant changes to Internet Explorer between the release of Windows XP and the recent release of IE 7.0. Although Microsoft has released numerous updates to Internet Explorer during this time period, until Service Pack 2, those updates were primarily security updates.

Before Service Pack 2 was released, some users began to suspect that IE development (in terms of potential enhancements to the product) had been abandoned once Microsoft had 'won the browser wars'. IE Product Manager Brian Countryman added to the fears of these users when he announced in an interview in 2003 that "IE6 SP1 is the final standalone installation," indicating that its far-off (in 2003) Codename Longhorn operating system would be the sole platform for which any further enhancements would be released.

Microsoft has since reversed that decision, and announced that version 7, like several other features originally intended for Windows Vista, would be available freely to all Windows XP users as well. Microsoft also re-committed itself to supporting and enhancing IE 6 for Windows XP users, by releasing Service Pack 2. It added several new features intended to enhance security, including a pop-up blocker.

[edit] Critism of Internet Explorer 7

Internet Explorer 7 also significantly falls short of web standards support ^[23]. Internet Explorer 7 is also criticized by users for not allowing customizability of toolbar buttons and toolbar layout.

[edit] Footnotes

1. ^  PNG Files Do Not Show Transparency in Internet Explorer, February 13, 2005.
2. ^  Transparent PNG Support, May 12, 2005.
3. ^  Cannot View Some PNG Images, May 12, 2005.
4. ^  PHP: imageinterlace, May 12, 2005.
5. ^  Forcing IE to Show Application/xhtml+xml pages, May 12, 2005.
6. ^  Does Microsoft Internet Explorer accept the media type application/xhtml+xml?, July 21, 2004.
7. ^  Sending XHTML as text/html Considered Harmful, February 13, 2005.
8. ^  /IE7/, May 12, 2005.
9. ^  Call to action: The demise of CSS hacks and broken pages, October 12, 2005.
10. ^  How to Protect Yourself From Vandals, Viruses If You Use Windows, May 12, 2005.
11. ^  Internet Explorer Is Too Dangerous to Keep Using, May 12, 2005.

[edit] See also

• Internet Explorer
• Criticism of Microsoft

[edit] References

1. ^ Vulnerability Report - Microsoft Internet Explorer 6.x. Secunia. Retrieved on April 7, 2006.
2. ^ Researchers warn of infectious Web sites (June 25, 2004). Retrieved on April 7, 2006.
3. ^ Vulnerability Note VU#713878. US-CERT (June 9, 2004). Retrieved on April 7, 2006.
4. ^ Perspective: A safe browser? No longer in the lexicon. CNet (July 7, 2005). Retrieved on April 7, 2006.
5. ^ Protected Mode in Vista IE7. Internet Explorer team blog. Microsoft (February 9, 2006). Retrieved on April 7, 2006.
6. ^ Wheeler, David (November 14, 2005). Why Open Source Software / Free Software (OSS/FS, FLOSS, or FOSS)? Look at the Numbers!.
7. ^ Thomson, Iain (October 9, 2002). Microsoft outlines security strategy. vnunet.com. Retrieved on April 7, 2006.
8. ^ Vulnerability Report - Microsoft Internet Information Services (IIS) 6. Secunia. Retrieved on April 7, 2006.
9. ^ Vulnerability Report - Apache 2.0.x. Secunia. Retrieved on April 7, 2006.
10. ^ Safe Personal Computing (December 12, 2004). Retrieved on April 7, 2006.
11. ^ Mossberg, Walt (September 16, 2004). How to Protect Yourself From Vandals, Viruses If You Use Windows. Personal Technology. Wall Street Journal. Retrieved on April 7, 2006.
12. ^ Vaughan-Nichols, Steven (June 28, 2004). Internet Explorer Is Too Dangerous to Keep Using. Linux & Open Source – Opinions. eWeek. Retrieved on April 7, 2006.
13. ^ Vulnerability Note VU#713878. US-CERT (June 9, 2004). Retrieved on April 7, 2006.
14. ^ Penn State Tells 80,000 Students To Chuck IE. InformationWeek (December 10, 2004). Retrieved on April 7, 2006.
15. ^ Seltzer, Larry (April 14, 2005). The Lame Blame of ActiveX. Security — Opinions. eWeek. Retrieved on April 7, 2006.
16. ^ Lemos, Robert (February 13, 2004). 200 days to fix a broken Windows. cNet. Retrieved on April 7, 2006.
17. ^ Greene, Thomas (July 20, 2001). Internet survives Code Red. The Register. Retrieved on April 7, 2006.
18. ^ The Basics of the IE Testing Matrix. Internet Explorer team blog. Microsoft (August 17, 2004). Retrieved on April 7, 2006.
19. ^ Handling MIME Types in Internet Explorer
20. ^ MIME Type Detection in Internet Explorer
21. ^ Next Explorer to fail Acid Test
22. ^ How to Crash Internet Explorer. Modern Life. Retrieved on February 11, 2007.
23. ^ Web browser standards support

[edit] External links

• Just what has Microsoft Been Doing for IE 7.0? (Slashdot)
• Internet Explorer is Evil!
• A 30-day relevation of a sequence of IE vulnerabilities
• Secunia - Vulnerability Report - Microsoft Internet Explorer 6.x
• Explorer Exposed!
• Windows Explorer vs. the Standards
• The Door Is Ajar — An "anti-IE" article by a Sun Microsystems technology director Tim Bray.
• Why You Should Dump Internet Explorer — An "anti-IE" article by a MCSE Daniel Miessler.
• StopIE — An "anti-IE" campaign by a web developer Stephen O'Brien
• Browse Happy — An "anti-IE" campaign by the Web Standards Project
• Drip — A utility to detect and measure IE's memory leaks.
• IE Leak Patterns — Microsoft's analysis of IE's memory leak problem.
• Internet Explorer Exploits
• Rendering problems in Internet Explorer
• How the web was almost won — Just how close did we come to a Net ruled by Microsoft? The "server wars" show a grim counterpart to the browser wars
• What's wrong with IE?