The unusual decision Microsoft made to release patches on Tuesday for unsupported versions of Windows was prompted by three NSA exploits that remained unaddressed from Aprils ShadowBrokers leak.

The worst of the bunch, an attack called ExplodingCan (CVE-2017-7269), targets older versions of Microsofts Internet Information Services (IIS) webserver, version 6.0 in particular, and enables an attacker to gain remote code execution on a Windows 2003 server.

All three attacks allow an adversary to gain remote code execution; one is EsteemAudit, a vulnerability in the Windows Remote Desktop Protocol (RDP) (CVE-2017-0176), while the other is EnglishmanDentist (CVE-2017-8487), a bug in OLE (Object Linking and Embedding). Microsoft said the patches are available for manual download.

ExplodingCan merits a closer look because of the wide deployment of IIS 6.0.

Generally, when you put a Windows machine on the internet, its going to be a server and its going to run a webserver, so there are production machines on the internet running IIS 6.0 right now, said Sean Dillon, senior analyst at RiskSense and one of the first to analyze the NSAs EternalBlue exploit that spread WannaCry ransomware on May 12.

Its probably already been exploited for months now, Dillon said. At least now theres a fix thats publicly available.

Microsoft released a hefty load of patches for supported products and services on Tuesday as part of its normal Patch Tuesday update cycle. Normally, patches for unsupported versions of Windows are available only for Microsoft customers on an expensive extended support contract. The companys decision to make all of those fixes public on Tuesday, it said, was prompted by an elevated risk for destructive cyber attacks.

Due to the elevated risk for destructive cyber attacks at this time, we made the decision to take this action because applying these updates provides further protection against potential attacks with characteristics similar to WannaCrypt, said Adrienne Hall, general manager of Microsofts Cyber Defense Operations Center.

In reviewing the updates for this month, some vulnerabilities were identified that pose elevated risk of cyber attacks by government organizations, sometimes referred to as nation-state actors or other copycat organizations, Hall said. To address this risk, today we are providing additional security updates along with our regular Update Tuesday service. These security updates are being made available toallcustomers, including those using older versions of Windows.

The ShadowBrokers leak in April unleashed a number of powerful Windows attacks into the public, allegedly belonging to the Equation Group, which is widely believed to the U.S. National Security Agency. Criminals and other nation states have already been leveraging the attacks to spread not only WannaCry ransomware, but also crytpocurrency mining utilities and other types of malware.

Microsoft said customers should not expect this type of patch release for unsupported products to become the norm. Some experts have been critical of Microsot, which also made a similar update available for unsupported products hours after the WannaCry outbreak.

I wish MS would stop releasing patches for xp/2003 it really harms efforts to get rid of legacy in the corporates

Quentyn Taylor (@quentynblog) June 13, 2017

Oh no. Take Windows XP off life support. Though it cannot die with dignity, it must be allowed to die. It will be messy. But this is cruel. https://t.co/euZVdTLC0z

Katie Moussouris (@k8em0) June 13, 2017

It was the right move by Microsoft, Dillon said. We saw the damage it can cause with WannaCry. Some of the most-used infrastructure, like SCADA systems, still run on XP whether theyre getting patches or not. When you have critical things [running on XP], its a good thing they released, but it should only be looked at as a temporary solution and people should look to upgrade off of legacy versions.

Some third-party services such as 0patch have provided micro-patches for some of these vulnerabilities on legacy versions, even before the ShadowBrokers leak, Dillon said. Hopefully people who are running legacy systems have looked into other means of patching beside official fixes, he said. Although, this is great that theres an official fix.

The remaining two vulnerabilities are a lesser severity but should be patched nonetheless on legacy systems.

EsteemAudit affects RDP, but only on XP and did not require a patch for modern versions of Windows. According to Microsoft, the vulnerability exists if the RDP server has smart card authentication enabled.

EnglishmanDentist, meanwhile, is triggered because Windows OLE fails to properly validate user input, Microsoft said.

Theres a whole wide assortment of exploits that were leaked, and weve only seen a few of them actively used at a mass scale. This is just plugging a hole before it becomes a bigger problem, Dillon said.

See the article here:

Rare XP Patches Fix Three Remaining Leaked NSA Exploits - Threatpost