<s>
Trust	B-General_Concept
boundary	I-General_Concept
is	O
a	O
term	O
used	O
in	O
computer	B-General_Concept
science	I-General_Concept
and	O
security	O
which	O
describes	O
a	O
boundary	O
where	O
program	O
data	O
or	O
execution	O
changes	O
its	O
level	O
of	O
"	O
trust	O
,	O
"	O
or	O
where	O
two	O
principals	B-General_Concept
with	O
different	O
capabilities	O
exchange	O
data	O
or	O
commands	O
.	O
</s>
<s>
An	O
example	O
of	O
an	O
execution	O
trust	B-General_Concept
boundary	I-General_Concept
would	O
be	O
where	O
an	O
application	O
attains	O
an	O
increased	O
privilege	O
level	O
(	O
such	O
as	O
root	B-Application
)	O
.	O
</s>
<s>
A	O
data	O
trust	B-General_Concept
boundary	I-General_Concept
is	O
a	O
point	O
where	O
data	O
comes	O
from	O
an	O
untrusted	O
source--for	O
example	O
,	O
user	O
input	O
or	O
a	O
network	B-Protocol
socket	I-Protocol
.	O
</s>
<s>
A	O
"	O
trust	B-General_Concept
boundary	I-General_Concept
violation	O
"	O
refers	O
to	O
a	O
vulnerability	O
where	O
computer	O
software	O
trusts	O
data	O
that	O
has	O
not	O
been	O
validated	O
before	O
crossing	O
a	O
boundary	O
.	O
</s>
