Microsoft has released an out-of-band patch for the vulnerability known as PrintNightmare that allows attackers to take control of a PC.
It is a critical bug in the Windows printer with exploit code in the public domain before Microsoft had the chance to issue a patch for it.
Administrators were advised to disable the Print Spooler service until a patch was available.
The remote code execution vulnerability occurs when the Windows Print Spooler service improperly performs privileged file operations, according to Microsoft.
The bug seems to be a serious problem at Microsoft, which has taken the strange step of releasing patches for Windows 7.
Windows 7 accounts for a smaller share of all Windows PCs sold in stores, but the numbers remained significant enough for Google to maintain Chrome support for Windows 7 until this month.
For more information, read the original story in ZDNet.