The vulnerability stemmed from two key issues: 1) The ClientSettings initialization and cookie validation in whitelist mode did not properly check allowed tokens before processing requests, as seen in the pre-patch has_cookie? method. 2) The Profiler's call method executed profiling logic before completing authorization checks. The fix (GHSA-j5hj-fhc9-g24m) moved security validations earlier in the pipeline and added proper token verification in ClientSettings#has_valid_cookie?. The commit shows critical changes to authorization flow in these functions.