Microsoft is again urging users to apply a patch for a vulnerability in the Windows Server service. The company reported earlier that a new variant of the Conficker worm has surfaced to target the flaw.
yet again to deploy the patch for a flaw affecting
the Windows Server service that was fixed in October.
The latest attacks are coming courtesy of a new variant of the Conficker
worm, identified by Microsoft
According to the company, the variant is hitting machines that have not applied
the fix, while also spreading via network shares by attempting to log in to
machines using a list of weak passwords.
The worm exploits a vulnerability caused by the Server service failing to
properly handle specifically crafted RPC (remote procedure call) requests. If
an exploit is successful, it could allow an attacker to execute code remotely
when file sharing is enabled.
The issue was the subject of a rare out-of-band
security patch by Microsoft
on Oct. 23. As attacks mounted, Microsoft
issued a follow-up advisory
on its Security
blog a month later.
"We encourage all customers to apply our most recent security updates
to help ensure that their computers are protected from attempted criminal
attacks," a Microsoft spokesperson said.
The Windows firewall also provides a defense against attacks in a default
setting because as it blocks hackers from reaching the RPC interface.
The flaw affects users of Microsoft Windows 2000, Windows XP and Windows
Vista, as well as Windows Server 2003 and Server 2008. On Windows 2000, XP and Server
2003, any anonymous user with access to the target network can deliver a
specially crafted network packet to exploit the vulnerability. However, on Vista
and Server 2008 systems, only an authenticated user with access to the target
network can deliver the packet.
"By default, Microsoft Windows XP, Windows Vista,
Windows Server 2003 and Windows Server 2008 customers will have this update
applied automatically through Automatic Updates," the spokesperson said. "We
encourage all customers to apply our most recent security updates to help
ensure that their computers are protected from attempted criminal attacks."