Page last updated at 11:08 GMT, Thursday, 10 July 2008 12:08 UK

Net address fix foxes web users

Screengrab of ZoneAlarm, CheckPoint
Lowering security settings can get ZoneAlarm users back online

Many users of the ZoneAlarm firewall have been floored by a fix to the net's addressing system.

Those hit found they could not get online after installing a Microsoft patch to close a security loophole.

Left open the flaw would have allowed malicious hackers to redirect users to fake websites, even if they typed the correct address.

Many net hardware and software firms prepared and applied patches this week to close the serious hole.

Firewall fix

The flaw in the net's Domain Name System (DNS) was discovered in March 2008 and since then many firms have been preparing patches and updates to ensure it cannot be exploited by hi-tech criminals.

On Tuesday Microsoft released its patch for DNS as part of its regular security update cycle.

However, many found that as soon as they applied the patch, known as KB951748, they could no longer go online.

BBC News website reader Chris Rogers applied the Microsoft patch to his own and his wife's computer but discovered that afterwards neither machine could get at e-mail or the web. His anti-virus software could no longer update either.

"Basically, the [Microsoft] update had crippled both PCs," he told BBC News.

The problems only affected those with machines running Windows XP or 2000.

A spokesman for Microsoft said PC owners were not contacting it about any problems the update caused.

Mr Rogers found restoring the PC's operating systems back to before the security update was installed, restored access to the net.

He, and many others, traced the problem to a conflict with the ZoneAlarm firewall.

As news of the problems spread, CheckPoint software, which owns ZoneAlarm, issued a statement about the problems.

While it prepared a fix for the fix, Checkpoint advised users to uninstall the Microsoft security update or temporarily lower the firewall settings to "medium".

Late on 9 July CheckPoint released an update to ZoneAlarm, version 7.0.483, that solved the conflict.

Mr Rogers said installing it and re-booting his machines fixed all the problems.

He said he could understand Microsoft being reticent with details about the patch given its sensitivity.

"But," he added "it would seem reasonable for [Microsoft] to test their patch against what is probably the most popular software firewall."


SEE ALSO
Fix found for net security flaw
09 Jul 08 |  Technology
Phishing attacks soar in the UK
15 Apr 08 |  Technology
Fears over online banking checks
13 Nov 07 |  Technology
Someone's watching you
14 Mar 08 |  Magazine
'Lax standards' on data security
14 Mar 08 |  UK Politics
Personal data privacy 'at risk'
21 Feb 08 |  Business
Taking cover from ID theft
22 Nov 07 |  Magazine

RELATED INTERNET LINKS
The BBC is not responsible for the content of external internet sites


FEATURES, VIEWS, ANALYSIS
Has China's housing bubble burst?
How the world's oldest clove tree defied an empire
Why Royal Ballet principal Sergei Polunin quit

BBC navigation

BBC © 2013 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.

Americas Africa Europe Middle East South Asia Asia Pacific