Now this doesn’t happen all that often, it must be really serious! An Out-of-Band patch from Microsoft (since it’s famous ‘Patch Tuesday‘ it only releases patches on the second Tuesday of each month) has been released for a new RPC flaw.
I’d imagine it’s similar to the RPC flaw that spawned such disasters as Blaster and Sasser in 2003/4.
Microsoft has released an emergency security update for a broad swath of its users that patches a critical security hole that is already being exploited in the wild.
The vulnerability – which has been subjected to “limited, targeted attacks” – could allow miscreants to create wormable exploits that remotely execute malicious code on vulnerable machines, Microsoft said. No interaction is required from the end user. It was the first patch released outside Microsoft’s regular update cycle in 18 months.
“This is a remote code execution vulnerability,” Microsoft’s out-of-band advisory warned. “An attacker who successfully exploited this vulnerability could take complete control of an affected system remotely.”
There is an active piece of malware in the wild using this, F-secure has already detected it and has a signature for Trojan-Spy:W32/Gimmiv.A.
This may have been running around in the wild for some time, perhaps in the underground community. There are always true remote exploits that are unknown to the mass community used by certain higher level groups.
This is the sixth time Microsoft has issued and out-of-band security update since October 2004 when it implemented its policy of releasing patches on the second Tuesday of each month, a company spokesman said. The last time an unscheduled patch update was issued was in April 2007 when it moved to fix a critical bug in the ANI animated cursor feature of Windows.
Thursday’s bulletin also marked the second time Microsoft has offered additional vulnerability details to security providers in advance. About an hour before the patch was released publicly, members of the Microsoft Active Protections Program (MAPP) received a briefing that allowed them to create signatures that detect exploits in anti-virus software and intrusion prevention systems.
Microsoft also offered a stunning amount of detail about the vulnerability to regular Joes here.
It’s only the 6th time this has happened since October 2004 (around 4 years) so you can see that it’s serious and you better install it across any networks you administer.
The update will require a reboot (as usual..).
Source: The Register