Flaw discovered in Symantec firewall

A vulnerability has been discovered in Symantec firewall products that would let a knowledgeable attacker hijack any connection to Symantec's software-based or appliance-based firewalls, thereby potentially gaining unauthorized access to internal corporate resources.

The discovery was made by security services firm Ubizen July 3, which contacted Symantec about the vulnerability. Both companies agreed to refrain from publicizing the problem until Symantec had prepared a software fix. This remedy has now been made available at Symantec's Web site for eight basic models of its Raptor, Enterprise Firewall and VelociRaptor firewall products.

The software patch remedies weaknesses in the algorithm used in the firewall to randomly generate initial sequence numbers. The main problem, it appears, is the algorithm wasn't generating new sequence numbers quickly enough to thwart potential hijacking attempts to break in.

"The algorithm for generating sequence numbers was flawed but has now been fixed," said Kristof Philipsen, network security engineer at Ubizen. The algorithm had only been changing random sequence numbers every 35 minutes, which left a window of time for hackers to try to hijack the session or insert data.

Philipsen said he discovered the problem when running a network penetration test on a customer's Symantec firewall using Ubizen's in-house tool called ISN Probe, which is available as an open-source tool for download over the Web.

The Ubizen engineer acknowledged that the flaw that had existed in Symantec's random-number generator was not necessarily easy for an attacker to exploit. "It would require a lot of skill," Philipsen said.

Potentially though, attackers could hijack encrypted or unencrypted sessions by a user connecting to Symantec firewalls. These include: Raptor Firewall 6.5 based on Windows NT, Raptor Firewall 6.5.3 on Solaris, Symantec Enterprise Firewall 6.5.2 for Windows 2000 and NT, Symantec Enterprise Firewall v7.0 for Solaris, Windows 2000 and NT, the VelociRaptor Model 500/700/1000 and Models 1100/1200/1300 as well as Symantec Gateway Security 5110/5200/5300.

Philipsen said the software patch, which is easy to install, fixes the random-number generator problem.

As to why it took a whole month for Symantec to prepare the software patch to fix the problem, Symantec's product manager Michele Araujo said Symantec was working closely with Ubizen on the algorithm flaw, but the process was slowed down when Ubizen employees close to the issue went on vacation.

"This is much longer than usual for us," conceded Symantec senior director of product management Barry Cioe.

Symantec has made the software fix available at http://securityresponse.symantec.com/.

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.

Ellen Messmer

Computerworld
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?