Christopher Budd, security program manager, said on Friday on the
Microsoft Security Response Center blog, that a patch should be part of the release.
"We are increasingly confident that we will have an update of appropriate quality for broad distribution in time for the May 8, 2007 monthly bulletin release. This will enable us and our customers to release and deploy the update as part of the regular monthly update process," he said.
"However, as I’ve mentioned before, because testing is ongoing and we are constantly evaluating the situation, this could change."
Budd added that Microsoft and its Security Response Alliance partners have discovered no exploits for the flaw in the past week.
On April 19, Budd said that Microsoft teams were working 24 hours a day to have a patch ready by 8 May.
He also cautioned that Microsoft researchers must test and develop 133 separate updates – one for every language for which the company produces software.
Public exploits, including a Metasploit module, were released earlier this month, but researchers said attacks were rare because the DNS server is generally not public facing. Intranets are at the greatest risk of exploitation, researchers said.
Kyle Haugsness of the SANS Internet Storm Center said this month that the organisation had confirmed two victims of DNS flaw exploits, both US universities.
Andrew Storms, director of security operations at nCircle, told SCMagazine.com that Microsoft deserves credit for being forthcoming with patch and vulnerability information.
"We haven’t seen any new bot activity or any new nefarious traffic [since last week] based on that," he said. "I partially account it to the workarounds being good. We might be seeing the new face of Microsoft on vulnerabilities. We really saw Microsoft come out on the forefront and provide more information than they had previous to that."
Microsoft has recommended a number of workarounds for the flaw, including blocking TCP and UDP port 445 and all unsolicited traffic on ports greater than 1024.
Ron O’Brien, senior security analyst at Sophos, told SCMagzine.com that the workarounds adequately blocked exploit code.
"One thing that I’ve heard is that the workaround was effective in blocking any exploit, for one because [the flaw] existed for as long as it did, it was a wake-up call to everyone who had never blocked an exploit to go ahead and do it," he said.