active? was only checked at the password step of sign-in. A user disabled
afterwards could (a) still complete the 2FA step and mint a valid session, and
(b) keep using any existing session until natural expiry, because per-request
auth only checked session expiry, not user status.
Three enforcement points:
- Mid-flow guard: verify_totp and webauthn_verify re-check active? before
start_new_session_for, clearing the pending session and rejecting if disabled.
- Request-time guard: find_session_by_cookie now uses Session.for_active_user,
so a session whose user is disabled no longer authenticates (authoritative,
catches any disable path including direct DB changes).
- Immediate cleanup: User#revoke_sessions_when_deactivated destroys a user's
sessions when status changes away from active, so access is revoked everywhere
at once rather than on the next request.
Tests cover the mid-flow TOTP rejection, request-time rejection of an existing
session after disable, session destruction on disable, and that unrelated
updates leave sessions intact.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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