Skip to main content
HubbaBubba
New Member
June 22, 2020
Question

SSL-VPN causing 100% CPU with NPS and Azure MFA Extension

  • June 22, 2020
  • 5 replies
  • 8435 views

Hi,

I have configured an existing SSL-VPN to use Radius. The Radius sends requests to a Microsoft NPS server with the Azure extension installed which will provide MFA requests.

All the config works great.

After several hours of running the server is maxing it's CPU at 100% on a COM surrogate process. Users get delays to the authentication request or none at all.

There is an event constantly logged that may be causing this issue:

Log Name: AuthZAdminCh Source: Microsoft-AzureMfa-AuthZ Date: 22/06/2020 09:46:16 Event ID: 3 Level: Critical User: NETWORK SERVICE Computer: Servername Description: NPS Extension for Azure MFA: CID: <> :Exception in Authentication Ext for User USername :: ErrorCode:: REQUEST_MISSING_CODE Msg:: Request is missing OTP Enter ERROR_CODE @ [link]https://go.microsoft.com/fwlink/?linkid=846827[/link] for detailed troubleshooting steps.

This request is coming from the FortiGate but does not relate to an active request for a user to log in, it appears to be an old request that does not timeout.

Can anyone point me to the settings that is causing these requests on the FortiGate?

    5 replies

    HubbaBubba
    New Member
    June 22, 2020

    After some testing and troubleshooting I cannot find a fix.

    The current workaround is to restart the NPS server every 3 hours.

     

    The full fix is to update the firmware on the firewall to Forti OS 6.0.9 or above which should happen in the next week on the managed firewall.

    Daas
    New Member
    July 31, 2020

    I am having the same issue.

     

    Did the upgrade to 6.0.9 fix the problem permanent? 

    HubbaBubba
    New Member
    July 31, 2020

    Hi,

    yes the upgrade fixed the problem permanently

     

    Cheers

    Thought Leadership. Security Summit. Thursday, November 12th, PGA National Resort, Palm Beach Gardens, FL.
    Thought Leadership. Security Summit. Thursday, October 8th. Disney's Grand Californian Hotel & SPA, Anaheim, CA.