The vulnerability manifests in the legacy cross-domain authentication flow handled by auth0-js. Key functions identified are those directly involved with: 1) Initiating username/password login via deprecated endpoints, 2) Generating auto-submitted forms without CSRF tokens, and 3) Managing cross-origin authentication sequences. These functions would appear in stack traces when processing malicious CSRF requests against the /usernamepassword/login endpoint with Legacy Lock API enabled. The evidence comes from Auth0's bulletin describing the vulnerable flow mechanics and the requirement to update auth0-js to 9.0.0 which removed this legacy functionality.