Last Call Review of draft-ietf-pals-mc-pon-04
review-ietf-pals-mc-pon-04-secdir-lc-hanna-2016-09-08-00

Request Review of draft-ietf-pals-mc-pon
Requested rev. no specific revision (document currently at 05)
Type Last Call Review
Team Security Area Directorate (secdir)
Deadline 2016-09-06
Requested 2016-08-25
Draft last updated 2016-09-08
Completed reviews Genart Last Call review of -04 by Roni Even (diff)
Secdir Last Call review of -04 by Steve Hanna (diff)
Rtgdir Early review of -04 by Geoff Huston (diff)
Assignment Reviewer Steve Hanna
State Completed
Review review-ietf-pals-mc-pon-04-secdir-lc-hanna-2016-09-08
Reviewed rev. 04 (document currently at 05)
Review result Has Issues
Review completed: 2016-09-08

Review
review-ietf-pals-mc-pon-04-secdir-lc-hanna-2016-09-08






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.




 




Summary: Ready with issues




 




The security considerations section of this document seems reasonable and correct. However, I’m concerned that bringing ICCP into the PON has some security risks that have not been properly called out and mitigated. As the Security Considerations
 section says:




 




   In many passive optical networks the optical paths between




   OLT and ONTs traverse publicly accessible facilities including




   public attachments (e.g. telephone poles)




 




Note that I’m pretty sure that ONT should be ONU here and in several other places in the Security Considerations.




 




My concern is that section 4.2 says that “When a fault is detected on its working PW (e.g., by VCCV BFD), a working OLT SHOULD turn off its associated PON interface and then send an ICCP message with PON State TLV with local PON Port
 State being set to notify the protection OLT of the PON fault.” Since the working PW has failed, the working OLT will presumably send this ICCP message to the protection PW over the PON. That means that any other authorized or unauthorized party on the PON
 could also send such a message. I’m not very familiar with ICCP but the Security Considerations section of RFC 7275 seems to say that ICCP messages are frequently authenticated only by looking at the source IP address, which is an exceedingly weak method of
 authentication susceptible to easy forgery. Using MD5 (as permitted by RFC 7275) isn’t much better. The impact of permitting attackers to easily forge ICCP messages on the PON is not clear to me but it seems that the attacker could at least prevent proper
 failover and maybe force failover or even force failure. Of course, an attacker on the PON could also just jam the PON by setting their laser always on but ICCP attacks would be much trickier to detect. I would suggest that TCP-AO be required at least for
 ICCP messages sent or received on the PON.




 




Two minor typos:




 




1)

     


In section 3, “protect OLTs” should be “protection OLTs”.




 




2)

     


In the Security Considerations, “ONT” should be “ONU”. At least, I assume so. If not, ONT should be defined.




 




Thanks for your consideration,




 




Steve