Recent SP Security Update causes IIS to throw a 503

Michèle Merlo 20 Reputation points

Hello The following march security update is causing an issue with my IIS: User's image

As soon as I install it a new DLL gets added "sprequestfilteringmodule.dll" and the IIS becomes unreachable (503 error). What's interesting upon further investigation is that the WSUS Application Pool can't be started (no error message is shown, it just immediatly stopps again). The WAS Service is up and running though. In the Event Viewer, there are errors from the WAS Service with the Event ID 5002. A restart didn't help, the server had to be restored in order to get the IIS fast online again. More info to the server: It's a Windows 2012 R2 Server running SharePoint 2013 and the IIS. Has anyone encountered a similiar problem with the March Update or maybe even found a solution? Thanks already for reading and have a nice day

Internet Information Services
Windows Server 2012
Windows Server 2012
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2 answers

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  1. Stefan Goßner 656 Reputation points Microsoft Employee
    3 people found this answer helpful.

  2. Emily Du-MSFT 44,146 Reputation points Microsoft Vendor

    It may be caused by the application pool identity has a wrong or non-decipherable password: WAS can’t repeatedly start the w3wp.exe with the custom account that was set for the application pool. In the Windows Events we will see warnings from WAS like Event ID 5002.

    Please go to IIS -> Select the application pool -> Advanced settings -> Identity -> Set as farm account with correct password. Then restart the application pool reset IIS.

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