<s>
Cisco	B-Device
PIX	I-Device
(	O
Private	O
Internet	O
eXchange	O
)	O
was	O
a	O
popular	O
IP	B-Protocol
firewall	B-Application
and	O
network	B-Protocol
address	I-Protocol
translation	I-Protocol
(	O
NAT	O
)	O
appliance	B-Architecture
.	O
</s>
<s>
In	O
2005	O
,	O
Cisco	O
introduced	O
the	O
newer	O
(	O
Cisco	B-Language
ASA	I-Language
)	O
,	O
that	O
inherited	O
many	O
of	O
the	O
PIX	O
features	O
,	O
and	O
in	O
2008	O
announced	O
PIX	O
end-of-sale	O
.	O
</s>
<s>
The	O
PIX	O
technology	O
was	O
sold	O
in	O
a	O
blade	B-Architecture
,	O
the	O
FireWall	B-Application
Services	O
Module	O
(	O
FWSM	B-Device
)	O
,	O
for	O
the	O
Cisco	B-Device
Catalyst	I-Device
6500	I-Device
switch	O
series	O
and	O
the	O
7600	O
Router	O
series	O
,	O
but	O
has	O
reached	O
end	O
of	O
support	O
status	O
as	O
of	O
September	O
26	O
,	O
2007	O
.	O
</s>
<s>
The	O
PIX	O
name	O
is	O
derived	O
from	O
its	O
creators	O
 '	O
aim	O
of	O
creating	O
the	O
functional	O
equivalent	O
of	O
an	O
IP	B-Protocol
PBX	O
to	O
solve	O
the	O
then-emerging	O
registered	O
IP	B-Protocol
address	I-Protocol
shortage	O
.	O
</s>
<s>
At	O
a	O
time	O
when	O
NAT	O
was	O
just	O
being	O
investigated	O
as	O
a	O
viable	O
approach	O
,	O
they	O
wanted	O
to	O
conceal	O
a	O
block	O
or	O
blocks	O
of	O
IP	B-Protocol
addresses	I-Protocol
behind	O
a	O
single	O
or	O
multiple	O
registered	O
IP	B-Protocol
addresses	I-Protocol
,	O
much	O
as	O
PBXs	O
do	O
for	O
internal	O
phone	O
extensions	O
.	O
</s>
<s>
When	O
they	O
began	O
,	O
RFC	O
1597	O
and	O
RFC	O
1631	O
were	O
being	O
discussed	O
,	O
but	O
the	O
now-familiar	O
RFC	B-Protocol
1918	I-Protocol
had	O
not	O
yet	O
been	O
submitted	O
.	O
</s>
<s>
The	O
PIX	O
quickly	O
became	O
one	O
of	O
the	O
leading	O
enterprise	O
firewall	B-Application
products	O
and	O
was	O
awarded	O
the	O
Data	O
Communications	O
Magazine	O
"	O
Hot	O
Product	O
of	O
the	O
Year	O
"	O
award	O
in	O
January	O
1995	O
.	O
</s>
<s>
Together	O
they	O
continued	O
development	O
on	O
Finesse	O
OS	O
and	O
the	O
original	O
version	O
of	O
the	O
Cisco	B-Device
PIX	I-Device
Firewall	I-Device
,	O
now	O
known	O
as	O
the	O
PIX	O
"	O
Classic	O
"	O
.	O
</s>
<s>
During	O
this	O
time	O
,	O
the	O
PIX	O
shared	O
most	O
of	O
its	O
code	O
with	O
another	O
Cisco	O
product	O
,	O
the	O
LocalDirector	B-Device
.	O
</s>
<s>
On	O
January	O
28	O
,	O
2008	O
,	O
Cisco	O
announced	O
the	O
end-of-sale	O
and	O
end-of-life	O
dates	O
for	O
all	O
Cisco	B-Device
PIX	I-Device
Security	O
Appliances	O
,	O
software	O
,	O
accessories	O
,	O
and	O
licenses	O
.	O
</s>
<s>
The	O
last	O
day	O
for	O
purchasing	O
Cisco	B-Device
PIX	I-Device
Security	O
Appliance	B-Architecture
platforms	O
and	O
bundles	O
was	O
July	O
28	O
,	O
2008	O
.	O
</s>
<s>
Cisco	O
ended	O
support	O
for	O
Cisco	B-Device
PIX	I-Device
Security	O
Appliance	B-Architecture
customers	O
on	O
July	O
29	O
,	O
2013	O
.	O
</s>
<s>
In	O
May	O
2005	O
,	O
Cisco	O
introduced	O
the	O
ASA	O
which	O
combines	O
functionality	O
from	O
the	O
PIX	O
,	O
VPN	B-Application
3000	O
series	O
and	O
IPS	O
product	O
lines	O
.	O
</s>
<s>
Beginning	O
with	O
PIX	O
OS	O
version	O
8.x	O
,	O
the	O
operating	B-General_Concept
system	I-General_Concept
code	O
diverges	O
,	O
with	O
the	O
ASA	O
using	O
a	O
Linux	B-Application
kernel	O
and	O
PIX	O
continuing	O
to	O
use	O
the	O
traditional	O
Finesse/PIX	O
OS	O
combination	O
.	O
</s>
<s>
The	O
PIX	O
runs	O
a	O
custom-written	O
proprietary	O
operating	B-General_Concept
system	I-General_Concept
originally	O
called	O
Finese	O
(	O
Fast	O
Internet	O
Service	O
Executive	O
)	O
,	O
but	O
the	O
software	O
is	O
known	O
simply	O
as	O
PIX	O
OS	O
.	O
</s>
<s>
Though	O
classified	O
as	O
a	O
network-layer	B-Application
firewall	I-Application
with	O
stateful	O
inspection	O
,	O
technically	O
the	O
PIX	O
would	O
more	O
precisely	O
be	O
called	O
a	O
Layer	O
4	O
,	O
or	O
Transport	O
Layer	O
Firewall	B-Application
,	O
as	O
its	O
access	O
is	O
not	O
restricted	O
to	O
Network	O
Layer	O
routing	O
,	O
but	O
socket-based	O
connections	O
(	O
a	O
port	O
and	O
an	O
IP	B-Protocol
Address	I-Protocol
:	O
port	O
communications	O
occur	O
at	O
Layer	O
4	O
)	O
.	O
</s>
<s>
Administrators	O
can	O
configure	O
the	O
PIX	O
to	O
perform	O
many	O
functions	O
including	O
network	B-Protocol
address	I-Protocol
translation	I-Protocol
(	O
NAT	O
)	O
and	O
port	O
address	O
translation	O
(	O
PAT	O
)	O
,	O
as	O
well	O
as	O
serving	O
as	O
a	O
virtual	B-Application
private	I-Application
network	I-Application
(	O
VPN	B-Application
)	O
endpoint	O
appliance	B-Architecture
.	O
</s>
<s>
The	O
PIX	O
became	O
the	O
first	O
commercially	O
available	O
firewall	B-Application
product	O
to	O
introduce	O
protocol	O
specific	O
filtering	O
with	O
the	O
introduction	O
of	O
the	O
"	O
fixup	O
"	O
command	O
.	O
</s>
<s>
The	O
PIX	O
"	O
fixup	O
"	O
capability	O
allows	O
the	O
firewall	B-Application
to	O
apply	O
additional	O
security	O
policies	O
to	O
connections	O
identified	O
as	O
using	O
specific	O
protocols	O
.	O
</s>
<s>
The	O
Cisco	B-Device
PIX	I-Device
was	O
also	O
one	O
of	O
the	O
first	O
commercially	O
available	O
security	O
appliances	O
to	O
incorporate	O
IPSec	B-Protocol
VPN	B-Application
gateway	O
functionality	O
.	O
</s>
<s>
Administrators	O
can	O
manage	O
the	O
PIX	O
via	O
a	O
command	B-Application
line	I-Application
interface	I-Application
(	O
CLI	O
)	O
or	O
via	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
.	O
</s>
<s>
They	O
can	O
access	O
the	O
CLI	O
from	O
the	O
serial	O
console	O
,	O
telnet	O
and	O
SSH	B-Protocol
.	O
</s>
<s>
GUI	B-Application
administration	O
originated	O
with	O
version	O
4.1	O
,	O
and	O
it	O
has	O
been	O
through	O
several	O
incarnations	O
:	O
</s>
<s>
Adaptive	O
Security	O
Device	O
Manager	O
(	O
ASDM	O
)	O
for	O
PIX	O
OS	O
version	O
7	O
and	O
greater	O
,	O
which	O
can	O
run	O
locally	O
on	O
a	O
client	O
or	O
in	O
reduced-functionality	O
mode	O
over	O
HTTPS	B-Protocol
.	O
</s>
<s>
Because	O
Cisco	O
acquired	O
the	O
PIX	O
from	O
Network	O
Translation	O
,	O
the	O
CLI	O
originally	O
did	O
not	O
align	O
with	O
the	O
Cisco	B-Protocol
IOS	I-Protocol
syntax	O
.	O
</s>
<s>
Starting	O
with	O
version	O
7.0	O
,	O
the	O
configuration	O
became	O
much	O
more	O
IOS-like	O
.	O
</s>
<s>
The	O
PIX	O
was	O
constructed	O
using	O
Intel-based/Intel	O
-compatible	O
motherboards	O
;	O
the	O
PIX	O
501	O
used	O
an	O
Am5x86	B-Device
processor	O
,	O
and	O
all	O
other	O
standalone	O
models	O
used	O
Intel	B-General_Concept
80486	I-General_Concept
through	O
Pentium	O
III	O
processors	O
.	O
</s>
<s>
The	O
PIX	O
boots	B-Application
off	O
a	O
proprietary	O
ISA	B-Architecture
flash	B-Device
memory	I-Device
daughtercard	B-Device
in	O
the	O
case	O
of	O
the	O
NTI	O
PIX	O
,	O
PIX	O
Classic	O
,	O
10000	O
,	O
510	O
,	O
520	O
,	O
and	O
535	O
,	O
and	O
it	O
boots	B-Application
off	O
integrated	O
flash	B-Device
memory	I-Device
in	O
the	O
case	O
of	O
the	O
PIX	O
501	O
,	O
506/506e	O
,	O
515/515e	O
,	O
525	O
,	O
and	O
WS-SVC-FWM-1-K9	O
.	O
</s>
<s>
The	O
latter	O
is	O
the	O
part	O
code	O
for	O
the	O
PIX	O
technology	O
implemented	O
in	O
the	O
Fire	O
Wall	O
Services	O
Module	O
,	O
for	O
the	O
Catalyst	B-Device
6500	I-Device
and	O
the	O
7600	O
Router	O
.	O
</s>
<s>
The	O
Adaptive	O
Security	O
Appliance	B-Architecture
is	O
a	O
network	B-Application
firewall	I-Application
made	O
by	O
Cisco	O
.	O
</s>
<s>
It	O
was	O
introduced	O
in	O
2005	O
to	O
replace	O
the	O
Cisco	B-Device
PIX	I-Device
line	O
.	O
</s>
<s>
Along	O
with	O
stateful	O
firewall	B-Application
functionality	O
another	O
focus	O
of	O
the	O
ASA	O
is	O
Virtual	B-Application
Private	I-Application
Network	I-Application
(	O
VPN	B-Application
)	O
functionality	O
.	O
</s>
<s>
It	O
also	O
features	O
Intrusion	O
Prevention	O
and	O
Voice	O
over	O
IP	B-Protocol
.	O
</s>
<s>
The	O
ASA	O
continues	O
using	O
the	O
PIX	O
codebase	O
but	O
,	O
when	O
the	O
ASA	O
OS	O
software	O
transitioned	O
from	O
major	O
version	O
7.X	O
to	O
8.X	O
,	O
it	O
moved	O
from	O
the	O
Finesse/Pix	O
OS	O
operating	B-General_Concept
system	I-General_Concept
platform	O
to	O
the	O
Linux	B-Application
operating	I-Application
system	I-Application
platform	O
.	O
</s>
<s>
It	O
also	O
integrates	O
features	O
of	O
the	O
Cisco	O
IPS	O
4200	O
Intrusion	O
prevention	O
system	O
,	O
and	O
the	O
Cisco	O
VPN	B-Application
3000	O
Concentrator	O
.	O
</s>
<s>
The	O
Cisco	B-Device
PIX	I-Device
VPN	B-Application
product	O
was	O
hacked	O
by	O
the	O
NSA-tied	O
group	O
Equation	O
Group	O
somewhere	O
before	O
2016	O
.	O
</s>
<s>
According	O
to	O
Ars	O
Technica	O
,	O
the	O
NSA	O
likely	O
used	O
this	O
vulnerability	O
to	O
wiretap	O
VPN-connections	O
for	O
more	O
than	O
a	O
decade	O
,	O
citing	O
the	O
Snowden	O
leaks	O
.	O
</s>
<s>
The	O
vulnerability	O
requires	O
that	O
both	O
SSH	B-Protocol
and	O
SNMP	B-Protocol
are	O
accessible	O
to	O
the	O
attacker	O
.	O
</s>
<s>
According	O
to	O
Ars	O
Technica	O
,	O
the	O
exploit	O
can	O
easily	O
be	O
made	O
to	O
work	O
against	O
more	O
modern	O
versions	O
of	O
Cisco	B-Language
ASA	I-Language
than	O
what	O
the	O
leaked	O
exploit	O
can	O
handle	O
.	O
</s>
<s>
A	O
use	O
after	O
free-bug	O
in	O
the	O
Secure	B-Protocol
Sockets	I-Protocol
Layer	I-Protocol
(	O
SSL	O
)	O
VPN	B-Application
functionality	O
of	O
the	O
Cisco	B-Language
Adaptive	I-Language
Security	I-Language
Appliance	I-Language
(	O
ASA	O
)	O
Software	O
could	O
allow	O
an	O
unauthenticated	O
remote	O
attacker	O
to	O
cause	O
a	O
reload	O
of	O
the	O
affected	O
system	O
or	O
to	O
remotely	O
execute	O
code	O
.	O
</s>
