[Sis-csi] noting unusual CCSDS security critique

Wed Oct 5 03:04:29 EDT 2005

I took a look at this paper and I agree, its certainly unusual.  But I 
mean "unusual" in the sense that its very naive and written from a 
perspective of "lets take Internet attacks and see how they can be 
applied to space."  Sure, some apply - in a manner of sorts.  But others 
don't.

Right off the bat, the author thinks that the only barrier to keeping 
someone out of a commercial satellite link is the high cost of a 
transmitter.  Yep, that's one.  But what about the high cost of a dish?  
Not to mention that a Big Ugly Disk (BUD) is something that neighbors 
notice and complain about - at least in my neighborhood (not to mention 
the TVI resulting from any sort of high powered transmitter - ever live 
near someone with an illegal linear amp on a CB radio?). 

It goes on to discuss source code theft - sure thats a problem but not 
just for space systems.  And the goal is to assume that systems are not 
cloaked under a false sense of security by keeping source code 
"secret."  Look what happened to the GSM A3 COMP128 algorithm that 
relied on remaining secret but was broken as soon as its detailed were 
made public.  Not terribly robust!  Linux, FreeBSD, OpenBSD, and even 
Solaris all provide source code yet remain relatively secure.  The paper 
talks about buffer overflows as the latest exploitation craze - but they 
are nothing new and have been around for a long, long time (I ran into 
my first one 30 years ago).

Then there is a survey of news reports of stolen codes, denial of 
service against military birds, reports of Falun Gong jamming, takeover 
of control centers, etc.  And then there is a section talking about 
video streams being sent over RTP port 160000?   What's this all about?  
Is anyone using RTP over satellites?  And given the description, this 
wouldn't matter if it was a terrestrial network or a network with a 
space segment.  The space segment just replaces a land-line and the 
description is of a typical man-in-the-middle attack (w/o calling it that).

Finally, this paper talks about CCSDS as if it were a single 
communications "entity" rather than as an organization that recommends 
standards.  A quote is "Satellites use the CCSDS C&DH, CFDP, and 
telemetry services to communicate with ground stations and other 
satellites."  Hmmm, CFDP was just used for the first time on a 
spacecraft in the past month.  Don't know of any CCSDS-compatible 
spacecraft with cross links.  Don't know what a "CCSDS C&DH" means - is 
this a data handler that speaks using the CCSDS telecommand and CCSDS 
telemetry standards?  The paper then goes on to talk about how one goes 
about analyzing and trying to break any system - boundary checking, 
field validation, null processing.  All good things to stress - but this 
is not a issue with CCSDS standards as much as it is with implementers 
of CCSDS standards.  Just like there are good implementations of 
protocol stacks and are bad implementations (FreeBSD vs. Win95 for 
example). 

"Traditional space communication design sees security design as an 
afterthought."  I don't know what "traditional" means in this context. 
If it means civil science - yep that's right.  It it means deep-space 
(e.g., MER) - right but who's got a 70m dish to talk to it?  If it means 
geo comsat birds - no, not true.  If it means manned space - again not 
true.  If it means military space - definitely not true.  If it means 
navigation (e.g.,GPS) - nope not true. 

While I'm not saying that the space segment is in great shape 
security-wise or that no more work needs to be done (farthest from the 
truth), this paper doesn't portray any semblance of message because it 
appears to be making acusations against CCSDS protocols without full 
knowlege or understanding and it could be talking about any other set of 
protocols (e.g., TCP/IP). 

IP-in-Space would suffer from the same sorts of threats as the author 
postulates for what is called "CCSDS."  IPSEC provides protection 
against upper layer attacks (above TCP) but IP is still vulnerable to 
DoS attacks, buffer overflows, bogus packet fields, etc.  And after all, 
IP is so well known that script kiddies can take it apart easily (not 
that I'm advocating that the relative obscurity of space-only protocols 
is a means of achieving security).  And IP has to ride over a link layer 
protcol whether that means Ethernet in a LAN, 802.11 in wireless 
applications, GSM or CDMA in cellular nets, or just about anything else 
that handles bits to/from the transmission media (e.g. RF, copper, 
fiber, laser, IR, tin cans & string).  Not sure why the paper plugs 
Cisco NBAR and CBAC - what's that got to do with anything being 
discussed?  Likewise with mentioning authentication for NTP (and 
contrary to what is said, the NTP RFC did include shared-key 
authentication).

Yep, it sure is an "unusual" paper.

Howie Weiss

Lloyd Wood wrote:

>I stumbled across:
>
>http://www.infosecwriters.com/texts.php?op=display&id=310
>
>Secure Communication in Space by Alain Charles Brainos II, East
>Carolina University, on 05/08/05
>
>This is a strange document, apparently written for some online
>competition -- but it attempts a security evaluation of parts of
>CCSDS (pages 11 and 12).
>
>Quite odd, and not something you see every day.
>
>L.
>
><http://www.ee.surrey.ac.uk/Personal/L.Wood/><L.Wood at eim.surrey.ac.uk>
>
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>

-- 

Howard Weiss
SPARTA, Inc.
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