Microsoft firewall could be security risk

IT security experts and vendors have welcomed the introduction of Windows Firewall, part of Windows XP Service Pack 2 (SP2), as a valuable way of protecting PCs. But while the firewall is an improvement, it falls short of the standard of protection expected of commercial firewalls, according to some industry observers.

Windows Firewall-which replaces the old Internet connection firewall-marks the first time all up-to-date PCs will have a firewall switched on by default, an important step in stopping the spread of viruses according to industry analysts.

However critics say the software suffers from two major flaws; it does not block outbound traffic, and it can be switched off by another application, possibly even by a clever worm.

Most commercial firewalls include a feature to stop all but authorized applications from sending data to the Internet; this stops malicious code from sending unauthorized communications, and also prevents PCs from being hijacked and used to send spam or participate in distributed denial-of-service attacks.

Windows Firewall only filters incoming traffic and allows any application to send outbound packets, a fact which some industry observers have said makes it less useful for serious protection.

"It still isn't as robust as many third-party host-based firewalls," wrote Jeff Fellinge, information security officer at media company aQuantive Inc., in a recent analysis of the firewall.

More seriously, rival firewall makers claim that the API (application program interface) used to manage the Windows Firewall could also be used by attackers to modify the software or turn it off. Major firewall makers, including Zone Labs, McAfee and Symantec are releasing SP2-compatible versions of their applications which disable Windows Firewall when they are installed, and enable it again when they are uninstalled. But if an installer can switch off Windows Firewall, so could an attacker, argues Zone Labs, maker of the popular ZoneAlarm firewall. The company said their products are locked-down in such a way that third-party applications can't disable firewall protection without uninstalling the software.

Microsoft admitted that, in some cases, malicious code could indeed switch the firewall off. However, this isn't so much a flaw as a limitation on the role firewalls should play in a company's security system, Microsoft said.

"An attacker could misuse that (administrative) capability," said Microsoft technical specialist David Overton. "But you're already in a compromised state, if you're at that point."

He said that Windows Firewall is designed to stop malicious transmissions to the PC, rather than protecting the PC once it's been infected. If malicious code makes it past the firewall, it is the role of anti-virus software to protect the machine, added Overton.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Matthew Broersma

Techworld.com
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?