Microsoft issued eight bulletins as part of this month's Patch Tuesday, including six that the company ranked "critical." One of the vulnerabilities is already under attack by hackers.
Microsoft pushed out eight
as part of this month's Patch Tuesday, including a fix
for a vulnerability currently under attack.
According to the advisory, hackers have begun launching limited, targeted
in an ActiveX control for the Microsoft Visual Basic
6.0 Runtime Extended Files. Visual Basic 6.0 Runtime Extended Files include
select ActiveX controls, libraries and tools delivered with the Visual Basic
6.0 Integrated Development Environment (IDE)
media and as an online release. The files are typically installed either by
Visual Basic 6.0 IDE or Microsoft.com.
According to Microsoft, hackers have painted a bull's-eye on a memory
corruption issue involving the Masked Edit ActiveX Control. In that case, the
ActiveX control fails to handle property values correctly, causing a buffer
overrun when used in Internet Explorer that could allow an attacker to run
arbitrary code and take over a vulnerable system.
As a workaround, organizations can follow the directions provided by
Microsoft to disable the ActiveX Control in Internet Explorer.
The Masked Edit issue is just one of six affecting Visual Basic 6.0 Runtime
Extended Files. The rest of the bulletin covers memory corruption issues
involving the Charts, DataGrid, FlexGrid and Hierarchical FlexGrid ActiveX
controls. Also addressed is an allocation error involving the Windows Common
ActiveX control that occurs when parsing a specially crafted AVI file.
All totaled, six of the eight bulletins-including the one dealing with
Visual Basic-are classified by Microsoft as "critical." The other
critical bulletins cover remote code execution issues in Microsoft Excel,
Internet Explorer, Word, Outlook and Windows.
covers three bugs, including two file format parsing
vulnerabilities Microsoft considers likely to see consistent exploit code.
Among the critical bulletins, Microsoft also declared one of the eight
vulnerabilities affecting Word and Outlook and three of the four affecting Internet
Explorer to be likely candidates for consistent exploit code.
Word and Outlook bugs
are rated "critical" for Word 2000 and Outlook 2007,
but "important" for other versions. The IE
affect multiple versions, including 7.0, across several
The two critical Windows bulletins address flaws in the Windows GDI
(graphics device interface) and Windows Search. The GDI
deals with two bugs, both of which can be exploited via a
specially crafted WMF image file. The first is the result of an integer
overflow situation that occurs when GDI improperly processes a malformed header
in a WMF image file. The second issue is due to a heap overflow vulnerability
caused by the way GDI handles file size parameters in WMF files.
There are also two bugs in Windows
that can permit a hacker to remotely execute arbitrary code if a
user either opens and saves a specially crafted saved-search file within Windows
Explorer or clicks on a malicious search URL.
In addition to the critical bulletins, there are two others rated
"important." The bulletins rated "important" plug security holes in SharePoint
and Windows Media
Center. The SharePoint bulletin
fixes a privilege escalation issue. The Windows
bulletin is focused on two vulnerabilities, the most serious of which can lead
to remote code execution.