Werk #11492: Auth cookies: Specify SameSite attribute to improve cookie security

Component GUI
Title Auth cookies: Specify SameSite attribute to improve cookie security
Date Sep 11, 2020
Checkmk Editon Checkmk Raw (CRE)
Checkmk Version 2.0.0i1
Level Trivial Change
Class Security Fix
Compatibility Compatible - no manual interaction needed

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/.

To the list of all Werks