After applying .NET security fixes released in September 2018 to address CVE-2018-8421 SharePoint workflows stop working

Stefan Goßner - September 14, 2018 - 16 Comments

After applying .NET Security Only patch to resolve CVE-2018-8421 (Remote Code Execution Vulnerability), all SharePoint out of the box Workflow fails to execute and the log will show an error like this:

09/13/2018 01:59:07.57 w3wp.exe (0x1868) 0x22FC SharePoint Foundation Workflow Infrastructure 72fs Unexpected RunWorkflow: 
Microsoft.SharePoint.SPException: <Error>
<CompilerError Line="-1" Column="-1" Text="Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file." />
<CompilerError Line="-1" Column="-1" Text="Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file." />
<CompilerError Line="-1" Column="-1" Text="Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file." />
<CompilerError Line="-1" Column="-1" Text="Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file." />
<CompilerError Line="-1" Column="-1"…

For more details about the issue, a technical explanation and the solution, please have a look at the blog post created by my colleauge Rodney Viana:

After installing .NET security patches to address CVE-2018-8421, SharePoint workflows stop working

16 Comments

Luigi Bruno
On 14. September 2018 Permalink

Are you aware of any potential impact on the custom workflows running on the Workflow Manager?

Reply
1. Stefan Goßner
  On 14. September 2018 Permalink
  
  Haven’t heard of any.
  
  Reply
Luigi Bruno
On 3. October 2018 Permalink

It looks like the problem affects custom workflows built using SharePoint Designer too, as per blog post at https://blogs.msdn.microsoft.com/rodneyviana/2018/09/13/after-installing-net-security-patches-to-address-cve-2018-8421-sharepoint-workflows-stop-working/.

Reply
1. Stefan Goßner
  On 4. October 2018 Permalink
  
  Hi Luigi,
  it affects all Workflows using the SharePoint 2010 engine. Of course also those created with SharePoint Designer.
  Cheers,
  Stefan
  
  Reply
Sibylla_B
On 10. October 2018 Permalink

Hello Stefan,
is this error solved by one of the updates released yesterday?
Thanks!
Sibylla
PS: Thank you for blogging all these information around updates! Unfortunately the (very good) rating for your blog posts does not work for me.

Reply
1. Stefan Goßner
  On 10. October 2018 Permalink
  
  Hi Sibylla,
  no the October CU does not include fixes for this.
  It is recommended to apply the script in the linked article to fix this.
  Cheers,
  Stefan
  
  Reply
  1. Sibylla_B
    On 10. October 2018 Permalink
    
    Thanks for the quick answer, Stefan!
    Do you know if it is planned to have this solved by a PU / CU in the future? (or another .NET update?)
    Sibylla
    
    Reply
    1. Stefan Goßner
      On 10. October 2018 Permalink
      
      Hi Sibylla,
      it is planned to release a fix – but this fix will be identical with the web.config changes listed in the article.
      Cheers,
      Stefan
      
      Reply
      1. Sibylla_B
        On 10. October 2018 Permalink
        
        Hi Stefan,
        thanks for all these information.
        Have a good day
        Sibylla
SteveAFC
On 17. October 2018 Permalink

Hello Stefan,
If we apply the changes to our web.config and then apply an older CU (For example June 2018), will the CU revert the web.config changes?
If so, does this mean that we would need to apply the web.config change after every CU until MSFT releases it’s own fix in a future CU?
Thanks.

Reply
1. Stefan Goßner
  On 18. October 2018 Permalink
  
  Hi Steve,
  installing an older CU should not revert these changes.
  Cheers,
  Stefan
  
  Reply
Dave Crosby
On 25. October 2018 Permalink

I installed the October .NET updates on a test machine and the SharePoint Workflow issue was resolved without applying the web.config workaround.

Reply
Nikisha Jain
On 11. January 2019 Permalink

Are there any patch updates which resolves the workflow issues for these faulty patches for Sharepoint designer workflows, Nintex workflows and Sharepoint workflows for sharepoint 2010 servers.

Reply
1. Stefan Goßner
  On 13. January 2019 Permalink
  
  Hi Nikisha,
  the most recent SharePoint Patches fix the issue for SharePoint Workflows.
  For Nintex Workflows Nintex has to provide a fix as we do not own their codebase.
  Or just apply the Workaround in the blog post from Rodney which fixes it for Nintex as well:
  https://blogs.msdn.microsoft.com/rodneyviana/2018/09/13/after-installing-net-security-patches-to-address-cve-2018-8421-sharepoint-workflows-stop-working/
  Cheers,
  Stefan
  
  Reply
Jignesh Joshi
On 23. October 2019 Permalink

Hello, We have tried this but this not working. We are still getting the same error. What else can be missing? We have checked on the server, there is no update installed (KB4457916/KB4457035). Still we are facing this issue.

Reply
1. Stefan Goßner
  On 23. October 2019 Permalink
  
  Hi Jignesh,
  if you need assistance to get this resolve I would recommend to open a ticket with Microsoft suppport.
  Cheers,
  Stefan
  
  Reply

Share this:

16 Comments

Leave a Reply Cancel reply