One month after disclosing dozens of software
vulnerabilities, which were then exploited by malicious code and a
new family of worms, Microsoft has published just one bulletin for
May, which covered a single non-critical vulnerability in some
versions of Windows.
Microsoft released a software patch and a security bulletin,
MS04-015, describing a vulnerability in the Windows Help and
Support Center (HSC). A problem with the way the HSC handles
information in URLs (uniform resource locators) could allow a
remote attacker to run malicious code on vulnerable Windows
machines, potentially giving them total control over compromised
systems. (See:
http://www.microsoft.com/technet/security/bulletin/ms04-015.mspx.)
HSC URLs, which use the HCP (Host Configuration Protocol) and
begin with "hcp://", link to help resources in Windows and are
similar to web URLs, which use HTTP (Hypertext Transfer Protocol)
and begin with "http://".
To take advantage of the hole, an attacker would have to trick
Windows users into clicking on an HSC link that was embedded in a
web page or an e-mail message formatted in HTML.
Once clicked, the attacker could open a Help window containing
content of the attacker's choosing. However, the user would still
need to interact with the attacker's Help page and perform other
actions to complete the attack.
Microsoft issued updates for the 32- and 64-bit editions of
Windows XP and Windows XP Service Pack 1, as well as 32- and 64-bit
editions of Windows Server 2003. Windows NT, 2000 and 98 are
unaffected by the HSC vulnerability.
The low-key security warning stands in marked contrast to April,
when Microsoft published four security bulletins, MS04-011, 012,
013 and 014. Those bulletins contained patches for 20 unique
software vulnerabilities, including critical holes in Microsoft's
Secure Sockets Layer library and the Local Security Authority
Subsystem Service (LSASS), which is used to authenticate users
locally and also in client-server environments. (See:
http://www.microsoft.com/technet/security/current.aspx.)
Malicious code to exploit those holes appeared within days of
publication of the bulletins and a new worm, Sasser, was released
on 1 May that exploited the LSASS hole and already may have
infected more than a million Windows machines worldwide.
Microsoft encouraged customers to install the May update at
their earliest opportunity, but cautioned that doing so would
disable some Windows features.
Citing its "defence in depth" strategy of securing its products,
Microsoft said MS04-015 patch removes a Windows XP feature that
enabled Windows to offer automatically the option of upgrading a
DVD device driver because the feature exposed users to unspecified
"malicious use."
Installing the May patch will also break a feature in the
Windows "Found New Hardware Wizard" that transmitted hardware
profile information after the wizard runs.
Customers who install the patch will receive error messages when
they try to use those features, Microsoft said.
Paul Roberts writes for IDG News
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