Microsoft has begun rolling out an emergency patch for Windows in order to fix a critical flaw in the Windows Print Spooler service.
This vulnerability, which goes by the name PrintNightmare, was revealed last week after security researchers accidentally released the exploit’s proof-of-concept (PoC) code.
Microsoft has released security updates to correct this flaw, which has been rated critical as attackers can remotely execute code with system-level privileges on affected computers.
The company has had to issue patches for Windows Server 2019, Windows Server 2012 R2, Windows Server 2008, Windows 8.1, Windows RT 8.1, and a variety of supported versions of Windows 10.
Microsoft has even decided to issue patches for Windows 7, which officially stopped receiving support last year.
At the moment, the firm has not yet released patches for Windows Server 2012, Windows Server 2016 and Windows 10 version 1607.
This patch is called CVE-2021-34527 and what it does is prevent a vulnerability in the Windows Print Spooler printing service, which allows third parties to execute files in administrator mode.
The company has also indicated that these patches should be arriving in the next few hours.
Depending on the version they have installed, users will receive the following patches:
KB5004945: Windows 10 version 2004 / 20H2 / 21H1.
KB5004946: Windows 10 version 1909.
KB5004947: Windows 10 version 1809 and Server 2019.
KB5004949: Windows 10 version 1803.
KB5004950: Windows 10 version 1507.
KB5004954: Windows 8.1 and Server 2012.
KB5004953: Windows 7 and Server 2008.
KB5004955: Windows Server 2008 SP2.
These patches have started to be released since July 6. Microsoft recommends installing them as soon as they are available for security reasons.