The connector OAuth popup posted the session token to window.opener with
a '*' target origin, so any page that opened the popup received it. An
attacker with an account on a multi-user deployment could start a flow for
their own pending session, get a victim to finish the provider consent, and
receive a token backed by the victim's Drive/SharePoint/Confluence tokens.
- Post popup results only to allowed frontend origins: the callback origin,
OIDC_FRONTEND_URL, the new CONNECTOR_ALLOWED_ORIGINS, and localhost:5173
when the callback runs on a loopback host.
- Render the success page from the callback itself so the token never
appears in a URL; callback-status ignores session_token/user_email params.
- ConnectorAuth accepts messages only from the popup it opened, on the
callback origin reported by /api/connectors/auth.
- /api/connectors/disconnect requires auth and only deletes the caller's
session.
- /api/connectors/sync and /api/remote reject session tokens the caller
does not own.
Fixes#2766
Alex