WinXP SP2 = security placebo?
Feature richness defeats commonsense
Windows attempts to control code execution with so-called "security zones" for online clients like Internet Explorer and Outlook Express. Since it's likely that everyone using the computer is an administrator, the idea here is to categorize Web content and software providers and their products as 'trusted' or 'untrusted.' Thus the user decides whether or not to allow provider X or Web site Y to run code on his machine, based on pure guesswork and vague impressions.
This approach is wrongheaded from the start. Users should not be expected to know whose content can be trusted and whose can't, or what code is safe to run and what isn't. And even when a user guesses right, malware can, and often does, execute in the wrong zone, as we have seen many times.
The default security settings for Internet Explorer are hardly changed from the risky and confusing ones Microsoft has been urging on users for years. Here's what we found:
ActiveX Controls: run and script functions are enabled by default if the control is "marked as safe". Downloading signed ActiveX Controls is enabled (no prompt), and unsigned ones are disabled (no prompt). Binary and script functions are enabled. This is far too confusing: ActiveX should have a simple on/off toggle, and should be kept off unless needed for something useful like Windows Update.
"Access data sources across domains" is disabled, and enabled for trusted sites. (We would leave it disabled.)
MetaRefresh is enabled. (We would leave it disabled.)
"Scripting of browser controls" is disabled for the Internet zone, and enabled for trusted sites. (We would leave it disabled.)
"Script initiated windows without size or position constraints" are disabled, but enabled for trusted sites. (We would leave it disabled.)
Drag & drop / copy & paste are enabled. (We would leave it disabled.)
"Installation of desktop items" gets a prompt, and is enabled for trusted sites. (We would require a prompt at all sites.)
"Launching programs and files in an IFRAME" gets a prompt, and is enabled for trusted sites. Most users probably have no idea what an IFRAME is. (We would leave it disabled.)
"Navigate sub-frames across domains" is enabled. (We would leave it disabled.)
"Open files based on content, not file extension" is enabled. (This is good.)
The pop-up blocker is enabled, but disabled for trusted sites. (We would leave it enabled.)
Userdata persistence is enabled. (We would leave it disabled.)
"Web sites in less privileged Web content zone can navigate into this zone" is enabled. (We would leave it disabled.)
"Paste operations via script" is enabled. (We would leave it disabled.)
Scripting of Java applets is enabled. (We would leave it disabled.)
In the Advanced dialog, things are fairly sensible overall, with a couple of exceptions:
"Check for server certificate revocation" is not selected. (We would leave it enabled.)
"Do not save encrypted pages to disk" is not selected. (We would leave it enabled.)
"Empty Temporary Internet Files folder when browser is closed" is not selected. (We would leave it enabled.)
Enable Profile Assistant is selected. (We would leave it disabled.)
The chief security problem with OE has been that it defaults to viewing HTML automatically. Plain text should be the default, to cut down on Web bugs and malicious scripts. However, we find that little has changed with SP2:
"Automatically log on to Windows Messenger" is selected. Messenger should not be enabled on most company workstations, although at least now there is an option.
"Notify for each read receipt" is set. It would be better to turn receipts off, to avoid accidentally confirming one's e-mail address to spammers.
The send-format defaults to HTML, a great waste of bandwidth, and an irritant to people, like myself, who force their -mail to display as plain text.
The Outlook Express security settings are basically sensible. Potentially dangerous file attachments can be blocked from being saved or opened, and are in fact blocked by default. This feature is good, so long as the mail client knows what to look for. It can probably be fooled a number of ways, and certainly is no substitute for antivirus software.
"Block images and other external content in HTML email" is selected. This helps cut down on Web bugs and inadvertent spam confirmations. However, an HTML off-switch forcing all email to display as plain text would be a good deal more effective at this, and thwart malicious scripts to boot.
Microsoft declined many opportunities to harden Windows XP in a meaningful way; that is, by disabling unnecessary services, enforcing the multiuser environment, setting sensible user and file permissions, and installing a fully-functional packet filter. The roster of missing security utilities, such as PGP, SSH, a proper wipe utility, etc., is immense.
The home user is the one most in need of good security configurations and tools, yet the one least served by SP2. Windows may be easy to use, but it is extremely complicated and difficult to administer, especially for security, with a tremendous number of hidden functions and many complex configuration interfaces. It should be left to the professional admin to enable services and understand their dependencies, not left to the home user to figure out which ones are risky, and which ones can safely be disabled.
The Security Center is a good idea, but as it's been implemented, it's little more than a gimmick that will lead to a false sense of security. Our test system remained vulnerable to a vast host of online threats, especially those involving user interaction. And that's a pity, because a Windows system can be hardened significantly so that even careless users will have trouble infecting it - so long as one knows how to go about it. The idea behind SP2 was to apply the kind of security know-how that users aren't expected to have via a major system update, so that people can venture onto the Internet without worry.
Unfortunately, Windows remains a quite dangerous system to connect to the Internet, and users are still very much on their own in terms of security solutions. ®
Thomas C Greene is the author of Computer Security for the Home and Small Office, a comprehensive guide to system hardening, malware protection, online anonymity, encryption, and data hygiene for Windows and Linux.