Why does my webserver have this in some links? (&csrfpId=)

Hi!

After some years with this Netgear Readynas 104 unit, with webserver on, and php, and mysqli and so on.....

I got som trubble and had to reset the Netgear Unit and start over from beginning.

So I did a  default factory reset. Installed my disk, and did the update the nas requested.

(I am currently on 6.10.4 Hotfix 1)

installed PHP,  MySQL server, PHPMyAdmin.

Now I can see that my server add some stuff in my webpages.

(And I have never had that before my default factory reset )

First: I can see this in the code on a webpage:

<script language="JavaScript" src="/csrf.js?i=0526" type="text/javascript"></script>

And at the bottom of the page:

<script type="text/javascript">
<!--
csrfInsert("csrfpId", "With a looooooooong number and letter combination");
//-->
</script>

And some of my links I do on some pages do have this in the browser:

&csrfpId=And that loooooooong number and letter combination

Now I wonder:

1. What is all this?
2. Why do I have this now and not before?
3.  Can I fix this in some way? So I dont have that stuff in my links?