Another IE zero day exploited

Second DirectShow vulnerability in six weeks labelled ‘extremely critical’.

Microsoft

has issued an advisory on a serious vulnerability in an

ActiveX

control in its

Internet Explorer

browser, the second zero-day alert in the same area of the product in recent months. The issue has been flagged as ‘extremely critical’ by vulnerability watchers at

Secunia

, and several reports of active exploitation in the wild have been seen, including some high-profile sites in China.

The flaw affects the DirectShow video streaming subsystem, hit by a similarly high-profile zero-day flaw in late May. This time the MSVidCtl.dll library is affected, and maliciously crafted files passed into affected systems can be used to remotely hijack vulnerable machines via silent drive-by download infections. The flaw is believed not to affect users of

Microsoft

‘s latest operating system versions,

Vista

and

Server 2008

.

The official advisory from

Microsoft

is

here

, with alerts and workarounds from

Secunia


here

and

SANS ISC


here

. More info is blogged by

Trend Micro


here

and

ScanSafe


here

, with a

McAfee

blog piece providing details of a range of similar attacks and an attractive diagram of the attack vector,

here

. A similar diagram can be found in a post from the

MMPC

on the previous DirectShow issue,

here

.

Posted on 07 July 2009 by

Virus Bulletin