Skip to Content
Security & privacy

Latest Windows patch fixes 4 zero-day flaws – Update now to protect your PC

If you keep an eye on the latest PC updates, you know that October’s Patch Tuesday was this week. It is traditionally the second Tuesday of every month that software developers release new patches for programs.

As with all newly-launched systems, the rollout of Windows 11 hasn’t exactly been smooth. Did you install Windows 11 yet? You should know about these problems first.

For Microsoft, October’s Patch Tuesday update brings a rather hefty amount of fixes. Here are all the things the latest update fixes, including four zero-day flaws.

Here’s the backstory

The latest update for Windows 10 fixes a host of problems, including four zero-day vulnerabilities. One of them has already been exploited by hackers. This poses a real risk to your computer.

The exploited vulnerability has been designated as CVE-2021-40449 and was discovered by a security researcher from Kaspersky Lab. Called a “Win32k Elevation of Privilege Vulnerability,” the company said it had been used in “widespread espionage campaigns against IT companies, military/defense contractors, and diplomatic entities.”

The remaining three zero-day exploits are:

  • DNS Server Remote Code Execution Vulnerability (CVE-2021-40469)
  • Windows Kernel Elevation of Privilege Vulnerability (CVE-2021-41335)
  • Windows AppContainer Firewall Rules Security Feature Bypass Vulnerability (CVE-2021-41338)

The update corrects a total of 81 flaws, of which:

  • 21 are Elevation of Privilege
  • Six are Security Feature Bypass
  • 20 are Remote Code Execution
  • 13 are Information Disclosure
  • Five are Denial of Service
  • Nine are Spoofing

The non-security portion of the latest Windows 10 update fixes a problem where Microsoft Office and Adobe Reader won’t open. There is also an update that fixes distortion in Cortana and an issue that causes your device to stop working after you restart.

Windows 11 gets its first update

Windows 11 also received its first update with October’s Patch Tuesday. Given the patch identifier of Windows 11 KB5006674, it brings the OS version to 22000.258.

It fixes one issue that Microsoft describes as “known compatibility issues between some Intel “Killer” and “SmartByte” networking software and Windows 11 (original release).” Without the patch, some websites might load slower than others, and VPN services could see degradation in functionality.

What you can do about it

Whether you are still on Windows 10 or have taken a leap of faith and updated to Windows 11, you need to ensure that you have the latest versions installed.

To install the updates on Windows 10 or 11, take the following steps:

  • Click the Start button on the bottom left. For Windows 11 it has moved to the middle of the taskbar.
  • Select Settings, then click Windows Update.
  • If you have the option, click Check for Updates.
  • Any additional patches and software fixes will be downloaded and installed onto your machine.

There is also an option that you can enable if you want your Windows-based computer to check for updates automatically. It will install them when you aren’t using your PC.

Keep reading

Warning: 24M webcam video records up for grabs on the Dark Web

Billions at risk after ‘high-level’ Google Chrome hacks

Stop robocalls once and for all

Robocalls are not only annoying, but they scam Americans out of millions every year. Learn Kim's tricks for stopping them for good in this handy guide.

Get the eBook