How can I remove server: cloudflare header in Azure app service?

Question

How can I remove server: cloudflare header in Azure app service?

fxazure4SBF 26

I've a project deploy to Azure app server, but I received issue from security team about header: server cloudflare
Can you help me how can I remove server: cloudflare header in Azure app service?

Dillon Silzer 57,826 Reputation points Volunteer Moderator

2022-09-27T05:35:00.783+00:00

Have you configured your domain and Azure App Service with Cloudflare?
fxazure4SBF 26 Reputation points

2022-09-27T05:45:37.663+00:00

this is screenshot about that issue
fxazure4SBF 26 Reputation points

2022-09-27T10:25:38.087+00:00

im not sure, domain is belong to client, I just receive report from security team about this header issue and need some help if I can fix it on azure side?
ajkuma 28,036 Reputation points Microsoft Employee Moderator

2022-09-28T18:29:48.657+00:00

fxazure4SBF-5632, As I understand you have mentioned, the domain belongs to your client and you are just accessing the URL/website. Just to clarify, did this issue happen recently or it’s been the case/reported since the beginning?

The issue could be incorrect configuration of any WAF or frontend proxy in front of App Service that your client may be using. Kindly check out this blog written by one of my peer for more info--
Azure Front Door (AFD) & App Gateway + App Service (Web App) unexpected issues and common solutions. If it’s fine, you may share the WebApp details here or I’ll follow-up with you privately.

1 answer

Your answer

Dillon Silzer 57,826 Reputation points Volunteer Moderator

2022-09-27T05:35:00.783+00:00

Have you configured your domain and Azure App Service with Cloudflare?
fxazure4SBF 26 Reputation points

2022-09-27T05:45:37.663+00:00

this is screenshot about that issue
fxazure4SBF 26 Reputation points

2022-09-27T10:25:38.087+00:00

im not sure, domain is belong to client, I just receive report from security team about this header issue and need some help if I can fix it on azure side?
ajkuma 28,036 Reputation points Microsoft Employee Moderator

2022-09-28T18:29:48.657+00:00

fxazure4SBF-5632, As I understand you have mentioned, the domain belongs to your client and you are just accessing the URL/website. Just to clarify, did this issue happen recently or it’s been the case/reported since the beginning?

The issue could be incorrect configuration of any WAF or frontend proxy in front of App Service that your client may be using. Kindly check out this blog written by one of my peer for more info--
Azure Front Door (AFD) & App Gateway + App Service (Web App) unexpected issues and common solutions. If it’s fine, you may share the WebApp details here or I’ll follow-up with you privately.

Answer 1

Lex Li (Microsoft) 6,037 Microsoft Employee

If your web solution uses Cloudflare as CDN in front of Azure App Service, then all web browsers connect to Cloudflare content servers first, and then the actual web pages are pulled from Azure App Service by Cloudflare.

In this manner, the Cloudflare header is in fact generated by Cloudflare servers, and it is impossible to disable them on Azure App Service side.

Please contact Cloudflare and ask them for assistance.

Share via

How can I remove server: cloudflare header in Azure app service?

1 answer

Your answer