ID: 11492
Title: Auth cookies: Specify SameSite attribute to improve cookie security
Component: Multisite
Level: 1
Class: Security fix
Version: 1.7.0i1
The authentication cookies of the Checkmk GUI (auth_[site]) previously relied
on the browsers default behaviour regarding the same site policy. This resulted
in a) an inconsistent cookie handling across the different browsers and b)
allow some sort of Cross-site request forgery (CSRF) attacks.
With this change we explicitly set the "SameSite=Lax" setting for all
authentication cookies created by logins after updating Checkmk.
For more information about this HTTP cookie setting have a look at
https://web.dev/samesite-cookies-explained/.