France and
Germany
have
advised their citizens to ditch Internet Explorer in the wake of reports that
an IE zero-day bug was involved in the massive cyber-attack against Google and
other companies.
Officials in both
countries issued
warnings in the past few days telling users to consider
switching from Internet Explorer to other Web browsers until Microsoft
delivers a patch. Researchers at McAfee have reported
seeing references to attack code for the vulnerability on mailing lists and
confirmed the presence of the code on at least one Website.
The IE vulnerability was
used in a spate of cyber-attacks targeting Google and other large corporate
networks. The attacks, which are believed to have come from China, have prompted
Google
to threaten to pull out of China altogether, and the U.S. State Department
plans to get
answers from
Chinathis
week regarding the incident.
Officials at Microsoft
said they are only seeing a limited
number of targeted attacks against a small subset of corporations.
“The attacks that we have
seen to date, including public proof-of-concept exploit code, are only
effective against Internet Explorer 6,” according to George Stathakopoulos,
general manager of Microsoft’s Trustworthy Computing Security group. “Based on
a rigorous analysis of multiple sources, we are not aware of any successful
attacks against IE7 and IE8 at this time. … We are not seeing any widespread
attacks by any means, and thus far we are not seeing attacks focused on
consumers.”
According to Microsoft,
the vulnerability exists as an invalid pointer reference within IE. Under
certain conditions, the invalid pointer can be accessed after an object is
deleted, the company's
advisory states.
“In a Web-based attack
scenario, an attacker could host a Web site that contains a Web page that is
used to exploit this vulnerability,” the Microsoft advisory continues. “In
addition, compromised Web sites and Web sites that accept or host user-provided
content or advertisements could contain specially crafted content that could
exploit this vulnerability. In all cases, however, an attacker would have no
way to force users to visit these Web sites. Instead, an attacker would have to
convince users to visit the Web site, typically by getting them to click a link
in an e-mail message or Instant Messenger message that takes users to the
attacker’s Web site."
The company urged users of
Internet Explorer 6 or 7 to update to Version 8, the most current edition of
the browser, rather than ditch IE altogether. Users are also advised to
set Internet and local intranet security zones to "high" to prompt
before running ActiveX controls and active scripting in these zones. In
addition, IE can be configured to disable active scripting. Instructions for
doing that can be found in the advisory.
As a tactical move to
avoid this particular attack, switching to another browser makes sense, Gartner
analyst John Pescatore told eWEEK. However, in the long term, “you’d be saying,
‘Don’t use any browser that will have unpatched vulnerabilities,’ and you would
not be able to use any browser—or any software, for that matter.
"IE6 should have been
abandoned long ago—saying, “Don’t use IE6” is a good idea, same about older
versions of Firefox [or other browsers],” he said.