After waking up from PrintNightmare, Microsoft has a workaround for another Windows Print Spooler vulnerability
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After the PrintNightmare fiasco of recent weeks, Microsoft has shared information about another Windows Print Spooler security vulnerability.
The issue is being tracked as CVE-2021-34481, and is described as a "Windows Print Spooler Elevation of Privilege Vulnerability". For the time being, there is no patch available, but Microsoft has offered details of a workaround that mitigates against potential attack -- but it is far from being an ideal solution.
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Microsoft is still investigating the newly revealed vulnerability. The company says of it: "An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations".
The company adds:
An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
An attacker must have the ability to execute code on a victim system to exploit this vulnerability.
The workaround that is offered up will secure systems until a patch is readied, but its not a solution that will please many people. Microsoft's answer is to simply disable the print spooler -- which has the rather drastic side effect of making it impossible to print either locally or remotely.
Microsoft describes how to implement the workaround:
Determine if the Print Spooler service is running
Run the following in Windows PowerShell:
Get-Service -Name Spooler
If the Print Spooler is running or if the service is not disabled, follow these steps:
Stop and disable the Print Spooler service
If stopping and disabling the Print Spooler service is appropriate for your environment, run the following in Windows PowerShell:
Stop-Service -Name Spooler -Force
Set-Service -Name Spooler -StartupType Disabled
Impact of workaround Stopping and disabling the Print Spooler service disables the ability to print both locally and remotely.
A fix is in the works, and while Microsoft will clearly be hoping to issue it on the next Patch Tuesday, this is certainly not guaranteed.
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