RE: Examples of lost security when integrating (secure) SW

There are many examples.  The one that comes to mind is in the multi-level
security world.  Let's say I have two computers: one is secure enough to
handle information that's unclassified & secret, and the other can handle
information that's secret & top secret (in each case with an acceptable
level of risk of the information flowing to the less classified level).
When you hook them together, you've now got unclassified -> top secret
connectivity, which increases the risk.  This is known as the "cascade
problem".

Cheers,
--Jeremy

> -----Original Message-----
> From: Magnus Therning [mailto:[email protected]]On Behalf Of
> Magnus Therning
> Sent: Tuesday, June 08, 2004 8:10 AM
> To: [email protected]
> Subject: Examples of lost security when integrating (secure) SW
> 
> 
> I just had a discussion with my colleagues regarding problems with
> security in larger systems that are composed by combining
> modules/components that individually are secure. Both my gut 
> and sources
> I have consulted says this is the case. However, I haven't 
> been able to
> find any examples of when this has happened!
> 
> Bruce Schneier spends a few pages in Secrets & Lies on the subject,
> without offering any examples of what can happen. I seem to remember
> some talk on a conference (was it Usenix?) a few years ago__I never
> attended it but I read the abstract of the 
> papers/talks--where a talk on
> security mentioned a case where the combination of two 
> security features
> effectively cancelled each other.
> 
> Can anyone offer any more concrete examples, ideally not only academic
> ones?
> 
> /M
> 
> -- 
> --------------------------------------------------------------
> ---------
> Magnus Therning                 Philips Research Laboratories 
> Eindhoven
> Phone: +31 40 2745179           (OpenPGP: 0x4FBB2C40)
> 
> Some operating systems are called 'user friendly', Linux however is
> 'expert friendly'.
>