Microsoft Patch Tuesday January Updates Addressed A Zero-Day In Defender

This Tuesday, Microsoft has released the first scheduled update bundle of 2021. With this January Patch Tuesday update, Microsoft has addressed a critical zero-day in Windows Defender. Also, they have addressed 82 other vulnerabilities that also included a publicly-known bug.

Microsoft Fixed Defender Zero-Day

With January Patch Tuesday, Microsoft has released the fix for the zero-day vulnerability in Microsoft Defender.

This vulnerability, CVE-2021-1647, was a critical-severity remote code execution flaw that first caught the attention of bad actors before receiving a fix.

This month, Microsoft has patched this bug by updating the Microsoft Malware Protection Engine. The patch will automatically update the users’ devices (when connected to the internet) without needing user interaction.

Nonetheless, all users can (and should) manually check their devices as well to have received the update. Simply open the Windows Security window on your device, click on the gear icon towards the bottom left of the window, then click “About”. Check for the presence of Engine version 1.1.17700.4.

Other Patch Tuesday January Updates

Apart from the above, Microsoft has also fixed an important-severity vulnerability affecting the Windows splwow64 service.

Tracked as CVE-2021-1648, the bug already received public attention after ZDI researchers disclosed the bug in December 2020. Exploiting this vulnerability could allow an attacker to gain elevated privileges on the target device.

In addition to these serious vulnerabilities, Microsoft has fixed 9 other critical severity flaws that could allow remote code execution.

Whereas, this update bundle also includes patches for 72 important severity vulnerabilities affecting different products. These vulnerabilities, upon exploitation, could lead to elevation of privileges, information disclosure, remote code execution, spoofing, tampering, and denial of service.

Since the updates are out, all Windows users must ensure updating their devices with the latest patches to stay protected. If the updates haven’t reached already, users can manually check for updates via this patch: All Settings > Update & Security > Check for updates.

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