Microsoft reacts fast to widespread zero-day exploitation.
Microsoft
have once again broken their monthly patching cycle to release a fix for a vulnerability which has been the focus of media attention as well as widespread reports of in-the-wild exploitation. The
animated cursor buffer-overflow flaw
, details of which first emerged late last week, has been spotted on a number of websites and has been subject of at least one spam campaign, trying to lure more victims to sites hosting the attacks.
After the initial reports of the flaw on Thursday, March 29th, by
Determina Security Research
, fears of possible exploitation were quickly realised, with web watchers at
Websense
reporting
over 100 sites carrying the exploit
, predominantly hosted in China, although
F-Secure
reported
only small numbers of affected users over the weekend. By the start of this week,
iDefense
reported spotting over 150 sites, and yesterday
Websense
issued a follow-up
warning of a spam campaign
, claiming to lead to ‘hot pictures’ of baldy popster Britney Spears, but in fact pointing at exploit sites.
Response to the vulnerability from security watchers was rapid, with unofficial patches for the issue released by both
eEye Digital Security
and the
Zeroday Emergency Response Team
(
ZERT
), the loose grouping of security experts formed last year to react to such incidents. Now
Microsoft
have also shown a turn of speed and released their own patch, well outside the usual ‘Patch Tuesday’ monthly scheme of issuing security fixes, which saw
no patches
released last month.
‘It’s a good sign that
Microsoft
can respond so speedily to a major issue like this,’ said
John Hawes
, Technical Consultant at Virus Bulletin. ‘It would of course be better if all vulnerabilities could be patched so promptly, without waiting for the monthly release to roll around, hoping that all the flaws we see in use out there will be covered. Once these patches are released, there’s also a time lag while slow adopters get around to applying them, so the malware writers wanting to exploit them still have available victims, but at least if fixes are available it is possible to exist online in some safety.’
Full details of the patch, which covers several other known security flaws, are available in a security bulletin from
Microsoft
here
. A full ‘Patch Tuesday’ release is expected next week.
Posted on 04 April 2007 by
Virus Bulletin
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