Earlier this week, we reported on the so-called PrintNightmare Windows flaw when Microsoft confirmed it. Affecting the Windows Print Spooler feature, the zero-day vulnerability was discovered last week. Days after confirming its existence, Microsoft is now rolling out an emergency patch for Windows.

Discovered by security researchers at Sangfor, the flaw became potent when the group accidentally released the proof-of-concept (PoC). This gave attackers the knowledge of how to exploit the flaw, meaning they could conduct remote execution code attacks to gain system-level privileges.

Microsoft confirmed the problem and assigned the vulnerability with the number CVE-2021-34527.

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Print Spooler is a service on Windows that runs by default. It is also an older component of the platform, which means all Windows versions are affected. Microsoft says it is now sending out a patch for the PrintNightmare vulnerability.

“We recommend that you install these updates immediately,” says Microsoft. “The security updates released on and after July 6, 2021 contain protections for CVE-2021-1675 and the additional remote code execution exploit in the Windows Print Spooler service known as ‘PrintNightmare’, documented in CVE-2021-34527.”

Patch Across Windows Versions

Microsoft is issuing updates for Windows 10, Windows Server 2019, Windows Server 2012 R2, Windows Server 2008, Windows 8.1, and Windows RT. The company clearly sees this as a major issue as a patch is also rolling out for Windows 7. That is a surprise because Microsoft no longer supports Win7.

This is an out of band emergency patch, another signal this is a big threat. Microsoft typically sends out security updates on its monthly Patch Tuesday. If a threat is deemed severe enough, the company will send out patches out of sync of Patch Tuesday.

Until users install the patch, Microsoft suggests disabling Windows Print Spooler or inbound remote printing.

Tip of the day: When using your Windows 10 laptop or convertible with a mobile hotspot you might want to limit the Internet bandwidth your PC uses. In our tutorial we are showing you how to set up a metered connection in Windows 10 and how to turn it off again, if needed.

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