By Robert McMillan
IDG News Service
April 18, 2007
Microsoft hopes to fix by May 8 a critical flaw in Windows Domain Name
System (DNS) servers that is being exploited by online criminals, the
company said late Tuesday.
Microsoft has been under pressure to address the flaw, reported last
week, since software that exploits it has now been widely disseminated,
and criminals are beginning to use it in attacks. On Monday, security
experts confirmed that variants of the Rinbot worm (also called Nirbot
by some vendors) had been scanning networks for vulnerable systems and
then attempting to exploit the DNS bug.
Microsoft characterizes the level of attacks as "not widespread."
The problem affects Windows 2000 and Windows Server 2003 systems, which
can be tricked into running unauthorized software when an attacker sends
them maliciously encoded RPC (Remote Procedure Call) packets to the DNS
server. The latest versions of Windows 2000 Professional, XP and Vista
are not vulnerable to this attack.
Microsoft has published a workaround for the problem, and the software
vendor is weighing whether to step up its response and fix it ahead of
May 8, the date of the company's next scheduled security update.
"While we don't have a firm estimate on when we'll complete our
development and testing of updates for this issue, we have teams around
the world working on it twenty-four hours a day, and hope to have
updates no later than May 8, 2007," wrote Microsoft security program
manager Christopher Budd, in a Tuesday blog posting. "However, this is a
developing situation and we are constantly evaluating the situation and
the status of our development and testing of updates," he added.
Microsoft was in a similar situation three weeks ago when attackers
began exploiting a similarly critical flaw in the software used by
Windows to read animated cursor files. Ultimately, Microsoft was forced
to release an early patch for that flaw.
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