It was found that cockpit before version 184 used glib's base64 decode functionality incorrectly resulting in a denial of service attack. An unauthenticated attacker could send a specially crafted request with an invalid base64-encoded cookie which could cause the web service to crash.
https://github.com/cockpit-project/cockpit/pull/10819
https://github.com/cockpit-project/cockpit/commit/c51f6177576d7e12
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3804