topic Re: CSRF problem with a reverse proxy in Splunk Enterprise

Any clues as to how to fix the header setting problem, or how to disable CSRF?

plaxosi — Tue, 29 Nov 2022 13:51:23 GMT

I have a problem when accessing Splunk over a reverse proxy. It seems that the required HTTP Header

X-Splunk-Form-Key

is not being set by the browser. This is despite the fact that the browser has the cookie

splunkweb_csrf_token_8443

from where (I guess) it copies the CSRF token. This results in error messages of the form

ERROR UiAuth - Request from 10.0.0.1 to "/splunk/en-GB/splunkd/__raw/servicesNS/userName/appName/search/jobs" failed CSRF validation -- expected "8617041906791058522", but instead cookie had "8617041906791058522" and header had ""

When accessing Splunk directly the HTTP header is set correctly and no errors occur.

There would be two ways to fix this: 1) find out why the header is not set, or 2) disable CSRF (as a workaround). But I have had no success with either.

Disabling CSRF should be possible using web.conf, but I have tried all combinations I can think of. For example, stanzas like this that try to cover all endpoints:

[expose:all]
methods = GET,POST
pattern = **
skipCSRFProtection = 1

or, more for more specific endpoints:

[expose:search]
methods = GET,POST
pattern = search/**
skipCSRFProtection = 1

But I continue to get the CSRF validation errors.

Any clues as to how to fix the header setting problem, or how to disable CSRF?

Thanks

Re: CSRF problem with a reverse proxy

jawaharas — Mon, 26 Aug 2019 04:34:01 GMT

Try increasing connection timeout between the browser and Splunk web as below:

server.socket_timeout = <integer>
* The timeout, in seconds, for accepted connections between the browser and  Splunk Web
* Default: 10

Can you get the timeout increased to 60 in web.conf and restart the Splunk instance?

server.socket_timeout = 60

Re: CSRF problem with a reverse proxy

davietch — Fri, 06 Sep 2019 08:16:17 GMT

Hi,

Were you able to fix this?
I've got the exact same issue :

failed CSRF validation -- expected "123456", but instead cookie had "123456" and header had ""

I've got Splunk 7.2.7 behind a Reverse proxy.

Re: CSRF problem with a reverse proxy

jawaharas — Fri, 06 Sep 2019 09:20:12 GMT

@davietch
Did you try to increase server.socket_timeout parameter value as mentioned in the answer?

Re: CSRF problem with a reverse proxy

davietch — Fri, 06 Sep 2019 09:30:37 GMT

Hi,

Yes, it does not work.

Re: CSRF problem with a reverse proxy

plaxosi — Sun, 08 Sep 2019 14:49:52 GMT

I have the answer to my own question. It turned out that a reverse proxy before the searchhead was changing the flags on the cookies, specifically in this case it was setting the HTTPOnly flag. Once that security feature on the reverse proxy was disable it all worked fine.

Re: CSRF problem with a reverse proxy

davietch — Mon, 09 Sep 2019 09:13:22 GMT

Thank you, it worked. I commented this line and the issue got away:

# Header edit Set-Cookie ^(.*)$ $1;HttpOnly;Secure

Although it worked, it'd be great to let this security feature enabled and make it work with Splunk....

Re: CSRF problem with a reverse proxy

sarvesh_11 — Fri, 21 Feb 2020 08:42:38 GMT

Hey, can you please guide, where is this code?
Where have you commented?

Re: CSRF problem with a reverse proxy

spunk_enthusias — Tue, 29 Nov 2022 13:28:31 GMT

[expose:all]
methods = GET,POST
pattern = **
skipCSRFProtection = 1

I'm trying to disable CSRF protection for other reasons and can confirm that this approach doesn't work for me.