I have reviewed this document as part of the security directorate's  ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the  security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

The protocol that this draft extends is one intended to be run over TLS and conducted between two endpoints controlled by the same administrative authority. The Security Considerations section duly makes this explicit and references another RFC which thoroughly discusses what can occur when these assumptions are violated. When the protocol is run as intended, there is no communication across trust boundaries and therefore the potential security concerns are minimal.