July 11, 2008
Security Firm Fixes DNS Flaw
Many net hardware and software firms have been working since March to help close a potentially dangerous loophole left open by the ZoneAlarm firewall, which would have allowed malicious hackers to redirect users to fake web sites, if left open.
Since the flaw's discovery in March 2008, many firms have been working to develop patches that ensure security of their machines was not compromised by the hi-tech criminals.On Tuesday Microsoft released its patch for Domain Name System as part of its regular security update cycle.
But several users, particularly those with machines running Windows XP or 2000, were surprised to find that as soon as they applied the patch, known as KB951748, they could no longer go online.
"Basically, the [Microsoft] update had crippled both PCs," said Chris Rogers, who applied the Microsoft patch to his own and his wife's computer before discovering that they were unable to receive e-mail or surf the Web.
He said he that once he restored both PCs' operating systems to before the security update was installed restored access to the net.
Rogers is one of several users who have traced the problem back to the ZoneAlarm firewall. Checkpoint software, owner of ZoneAlarm, has issued a statement about the problems.
Checkpoint instructed its users to uninstall the Microsoft security update or temporarily lower the firewall settings to "medium" while it prepared a way to fix the problem.
CheckPoint released an update to ZoneAlarm, version 7.0.483, that solved the conflict late Wednesday evening.
Mr. Rogers said the new version fixed the problems, adding that e could understand Microsoft being reticent with details about the patch given its sensitivity.
"But," he said "it would seem reasonable for [Microsoft] to test their patch against what is probably the most popular software firewall."
On the Net:
- Microsoft Knowledge Base article on DNS flaw - KB951748
- Checkpoint on Zone Alarm problems
- Microsoft security bulletin about DNS flaw