<s>
What	O
You	O
Cache	O
Is	O
What	O
You	O
Get	O
(	O
WYCIWYG	B-Protocol
)	O
is	O
a	O
Uniform	O
Resource	O
Identifier	O
(	O
URI	O
)	O
scheme	O
commonly	O
displayed	O
in	O
the	O
address	O
bar	O
of	O
Gecko-based	O
Web	B-Application
browsers	I-Application
like	O
Mozilla	B-Application
Firefox	I-Application
as	O
when	O
the	O
Web	B-Application
browser	I-Application
is	O
retrieving	O
cached	B-Protocol
information	O
.	O
</s>
<s>
WYCIWYG	B-Protocol
is	O
a	O
play	O
on	O
the	O
related	O
acronym	O
WYSIWYG	B-Application
(	O
What	B-Application
You	I-Application
See	I-Application
Is	I-Application
What	I-Application
You	I-Application
Get	I-Application
)	O
.	O
</s>
<s>
Mozilla	B-Application
Firefox	I-Application
implements	O
a	O
registered	O
,	O
strictly	O
internal	O
URI	O
scheme	O
to	O
sort	O
and	O
later	O
reference	O
locally	O
cached	B-Protocol
pages	O
that	O
were	O
generated	O
or	O
modified	O
by	O
a	O
script	O
on	O
the	O
client	O
side	O
(	O
a	O
common	O
practice	O
for	O
Web	O
2.0	O
sites	O
)	O
.	O
</s>
<s>
In	O
2007	O
Michał	O
Zalewski	O
reported	O
that	O
it	O
was	O
possible	O
to	O
bypass	O
the	O
same-origin	O
checks	O
and	O
read	O
from	O
cached	B-Protocol
(	O
wyciwyg	B-Protocol
)	O
documents	O
.	O
</s>
<s>
This	O
could	O
have	O
enabled	O
an	O
attacker	O
to	O
steal	O
sensitive	O
data	O
,	O
perform	O
cache	B-General_Concept
poisoning	I-General_Concept
and	O
execute	O
their	O
own	O
code	O
or	O
display	O
own	O
content	O
with	O
URL	O
bar	O
and	O
SSL	O
certificate	O
data	O
of	O
the	O
original	O
page	O
(	O
URL	B-Protocol
spoofing	I-Protocol
)	O
.	O
</s>
<s>
This	O
was	O
fixed	O
in	O
Firefox	B-Application
2.0.0.5	O
and	O
SeaMonkey	B-Language
1.1.3	O
.	O
</s>
