Having a secure operating environment is arguably one of the most important aspects of one's digital life. Although security vulnerabilities are unfortunately a rather common occurrence, so are the updates patching them, thankfully. One such update has now been issued by Microsoft.

Yesterday, it emerged that Google security researcher Tavis Ormandy had found what he deemed to be a "crazy bad" security vulnerability in Windows.

I think @natashenka and I just discovered the worst Windows remote code exec in recent memory. This is crazy bad. Report on the way. ??? — Tavis Ormandy (@taviso) May 6, 2017

Now, according to Microsoft's Simon Pope, the Group PM Manager at the company's Security Research Center, the issue has been fixed:

Please note, @taviso @natashenka that Microsoft just released a fix to an RCE in Defender. https://t.co/Pz7HQBNMtX — Simon Pope (@skjpope) May 9, 2017

The Security TechCenter Library listing reveals a Security Advisory through which both enterprise and non-enterprise customers are informed that Microsoft has issued an update for a security vulnerability in its Malware Protection Engine. This security flaw allowed for a remote code execution exploit to be undertaken, thus putting users at risk.

In the words of the company:

The update addresses a vulnerability that could allow remote code execution if the Microsoft Malware Protection Engine scans a specially crafted file. An attacker who successfully exploited this vulnerability could execute arbitrary code in the security context of the LocalSystem account and take control of the system.

The latest version of the Malware Protection Engine which still contains this flaw is 1.1.13701.0, while the one that has the patch is version 1.1.13704.0. The affected programs are as follows:

Microsoft Forefront Endpoint Protection 2010

Microsoft Endpoint Protection

Microsoft Forefront Security for SharePoint Service Pack 3

Microsoft System Center Endpoint Protection

Microsoft Security Essentials

Windows Defender for Windows 7

Windows Defender for Windows 8.1

Windows Defender for Windows RT 8.1

Windows Defender for Windows 10, Windows 10 1511, Windows 10 1607, Windows Server 2016, Windows 10 1703

Windows Intune Endpoint Protection

Needless to say, the flaw in all of these products covered by CVE-2017-0290 is labeled "Critical".

In terms of user action required in regards to this update, Microsoft states:

In response to a constantly changing threat landscape, Microsoft frequently updates malware definitions and the Microsoft Malware Protection Engine. In order to be effective in helping protect against new and prevalent threats, antimalware software must be kept up to date with these updates in a timely manner. For enterprise deployments as well as end users, the default configuration in Microsoft antimalware software helps ensure that malware definitions and the Microsoft Malware Protection Engine are kept up to date automatically. Product documentation also recommends that products are configured for automatic updating.

So, if you are running either of the software products listed in the previous paragraph, make sure you either have auto-update turned on, or you manually update to the version with the patched flaw.

Source: Simon Pope (Twitter), Security TechCenter Library