Last Call Review of draft-ietf-ippm-ioam-data-11
review-ietf-ippm-ioam-data-11-secdir-lc-emery-2020-12-10-00

Reviewer: Shawn M. Emery
Review result: Ready with nits

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.

This standards track draft specifies data fields in the In-situ Operations,
Administration,
and Maintenance (IOAM) scheme.  The data fields contain operational and
telemetry
information in a network domain.  "In-situ" refers to the fact that the
associated data is
actually encapsulated in the data packet itself rather than through a
separate OAM
packet.

The security considerations section does exist and describes multiple
vulnerabilities
to the IOAM.  Attackers can create both false-positives and false-negatives
in regards
to failures or the true state of the domain.  This can eventually lead to
DoS attacks.
Another form of DoS is by crafting an IOAM header to packets thereby
increasing the
resources required or exceeding the packet beyond the network's MTU size.

Verifying the path of the data packets is deferred to
draft-ietf-sfc-proof-of-transit's security
consideration section which has good coverage and ways to mitigate the
various attacks
on the protocol.  Eavesdropping is also possible, which can reveal
operational and telemetry
data of the network domain.

IOAM also utilizes timestamps, in which an attack on the time
synchronization protocol can
affect the timestamp fields in IOAM.  In addition the management
functionality of IOAM could
also be targeted, but suggests authentication and integrity checks to
protect against said attacks.

Various measures against these attacks are not prescribed based on the fact
that this specification
is about the data fields of IOAM.  However, I think it would be beneficial
to provide some guidance
(at least for future specifications) for each of these attacks
that utilize these data fields else why
articulate the security issues at all?

General comments:

None.

Editorial comments:


None.


Shawn.
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