IT Pro is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

Microsoft fixes actively exploited Defender zero-day flaw

The firm's latest Patch Tuesday release includes fixes for a total of 83 vulnerabilities across Windows, Azure and more

A Windows update ready to be installed on a laptop

Microsoft has released a fix for the zero-day remote access exploit recently uncovered in its Defender antivirus service.

The fix arrives in the company's monthly set of security patches, known as 'Patch Tuesday', which included patches for a total of 83 vulnerabilities across a wide range of products, including Windows, Azure and other Microsoft services. 

The zero-day exploit is tracked as CVE-2021-1647 and is described as a remote code execution (RCE) bug that allows threat actors to embed code on vulnerable devices by tricking users into opening a loaded document on a system with Microsoft Defender installed. 

Microsoft said that despite exploitation being detected in the wild, the technique was not functional in all situations, suggesting that it is still at a 'proof-of-concept' stage. However, the company warned that the code could evolve into more reliable attacks. 

To protect against any future attacks,  Microsoft has released patches for the Microsoft Malware Protection Engine, which will be installed automatically unless blocked by system administrators.

Alongside the Defender zero-day bug, the tech giant has also released a patch for a flaw in the Windows splwow64 service. This was tracked as CVE-2021-1648 and could be used to elevate the privileges of attack codes. This hasn't been exploited in the wild, according to Microsoft, but system admins have been advised to apply the patches to avoid any future problems. 

Microsoft is not the only firm starting 2021 with patches, as Adobe has released its first major batch of security fixes. On Tuesday, the software firm released a number of security advisories for vulnerabilities in seven different products: Photoshop, Illustrator, Animate, Bridge, InCopy, Captivate and Campaign Classic.

The first of these fixes have already been applied to the Photoshop image creation software on Windows and macOS-based machines. It is tracked as CVE-2021-21006 and can be used to trigger arbitrary code execution.

Featured Resources

The Total Economic Impact™ Of Turbonomic Application Resource Management for IBM Cloud® Paks

Business benefits and cost savings enabled by IBM Turbonomic Application Resource Management

Free Download

The Total Economic Impact™ of IBM Watson Assistant

Cost savings and business benefits enabled by Watson Assistant

Free Download

The field guide to application modernisation

Moving forward with your enterprise application portfolio

Free Download

AI for customer service

Discover the industry-leading AI platform that customers and employees want to use

Free Download

Recommended

Kaspersky exposes MysterySnail zero-day exploit in Windows
zero-day exploit

Kaspersky exposes MysterySnail zero-day exploit in Windows

13 Oct 2021

Most Popular

Why convenience is the biggest threat to your security
Sponsored

Why convenience is the biggest threat to your security

8 Aug 2022
UK water supplier confirms hack by Cl0p ransomware gang
ransomware

UK water supplier confirms hack by Cl0p ransomware gang

16 Aug 2022
How to boot Windows 11 in Safe Mode
Microsoft Windows

How to boot Windows 11 in Safe Mode

29 Jul 2022