<s>
POODLE	B-Protocol
(	O
which	O
stands	O
for	O
"	O
Padding	B-Protocol
Oracle	I-Protocol
On	I-Protocol
Downgraded	I-Protocol
Legacy	I-Protocol
Encryption	I-Protocol
"	O
)	O
is	O
a	O
security	O
vulnerability	O
which	O
takes	O
advantage	O
of	O
the	O
fallback	O
to	O
SSL	O
3.0	O
.	O
</s>
<s>
Bodo	O
Möller	O
,	O
Thai	O
Duong	O
and	O
Krzysztof	O
Kotowicz	O
from	O
the	B-Application
Google	I-Application
Security	O
Team	O
discovered	O
this	O
vulnerability	O
;	O
they	O
disclosed	O
the	O
vulnerability	O
publicly	O
on	O
October	O
14	O
,	O
2014	O
(	O
despite	O
the	O
paper	O
being	O
dated	O
"	O
September	O
2014	O
"	O
)	O
.	O
</s>
<s>
On	O
December	O
8	O
,	O
2014	O
a	O
variation	O
of	O
the	O
POODLE	B-Protocol
vulnerability	I-Protocol
that	O
affected	O
TLS	B-Protocol
was	O
announced	O
.	O
</s>
<s>
The	O
CVE-ID	O
associated	O
with	O
the	O
original	O
POODLE	B-Protocol
attack	I-Protocol
is	O
.	O
</s>
<s>
F5	O
Networks	O
filed	O
for	O
as	O
well	O
,	O
see	O
POODLE	B-Protocol
attack	I-Protocol
against	O
TLS	B-Protocol
section	O
below	O
.	O
</s>
<s>
To	O
mitigate	O
the	O
POODLE	B-Protocol
attack	I-Protocol
,	O
one	O
approach	O
is	O
to	O
completely	O
disable	O
SSL	O
3.0	O
on	O
the	O
client	O
side	O
and	O
the	O
server	O
side	O
.	O
</s>
<s>
However	O
,	O
some	O
old	O
clients	O
and	O
servers	O
do	O
not	O
support	O
TLS	B-Protocol
1.0	O
and	O
above	O
.	O
</s>
<s>
Thus	O
,	O
the	O
authors	O
of	O
the	O
paper	O
on	O
POODLE	B-Protocol
attacks	I-Protocol
also	O
encourage	O
browser	O
and	O
server	O
implementation	O
of	O
TLS_FALLBACK_SCSV	O
,	O
which	O
will	O
make	O
downgrade	O
attacks	O
impossible	O
.	O
</s>
<s>
Another	O
mitigation	O
is	O
to	O
implement	O
"	O
anti-POODLE	O
record	O
splitting	O
"	O
.	O
</s>
<s>
A	O
full	O
list	O
of	O
browser	O
versions	O
and	O
levels	O
of	O
vulnerability	O
to	O
different	O
attacks	O
(	O
including	O
POODLE	B-Protocol
)	O
can	O
be	O
found	O
in	O
the	O
article	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
.	O
</s>
<s>
Opera	B-Application
25	O
implemented	O
this	O
mitigation	O
in	O
addition	O
to	O
TLS_FALLBACK_SCSV	O
.	O
</s>
<s>
Google	B-Application
's	I-Application
Chrome	B-Application
browser	I-Application
and	O
their	O
servers	O
had	O
already	O
supported	O
TLS_FALLBACK_SCSV	O
.	O
</s>
<s>
Google	B-Application
stated	O
in	O
October	O
2014	O
it	O
was	O
planning	O
to	O
remove	O
SSL	O
3.0	O
support	O
from	O
their	O
products	O
completely	O
within	O
a	O
few	O
months	O
.	O
</s>
<s>
Fallback	O
to	O
SSL	O
3.0	O
has	O
been	O
disabled	O
in	O
Chrome	B-Application
39	O
,	O
released	O
in	O
November	O
2014	O
.	O
</s>
<s>
SSL	O
3.0	O
has	O
been	O
disabled	O
by	O
default	O
in	O
Chrome	B-Application
40	O
,	O
released	O
in	O
January	O
2015	O
.	O
</s>
<s>
Mozilla	B-Operating_System
disabled	O
SSL	O
3.0	O
in	O
Firefox	B-Application
34	O
and	O
ESR	O
31.3	O
,	O
which	O
were	O
released	O
in	O
December	O
2014	O
,	O
and	O
added	O
support	O
of	O
TLS_FALLBACK_SCSV	O
in	O
Firefox	B-Application
35	O
.	O
</s>
<s>
Microsoft	O
published	O
a	O
security	O
advisory	O
to	O
explain	O
how	O
to	O
disable	O
SSL	O
3.0	O
in	O
Internet	B-Application
Explorer	I-Application
and	O
Windows	B-Application
OS	I-Application
,	O
and	O
on	O
October	O
29	O
,	O
2014	O
,	O
Microsoft	O
released	O
a	O
fix	O
which	O
disables	O
SSL	O
3.0	O
in	O
Internet	B-Application
Explorer	I-Application
on	O
Windows	B-Application
Vista	O
/	O
Server	O
2003	O
and	O
above	O
and	O
announced	O
a	O
plan	O
to	O
disable	O
SSL	O
3.0	O
by	O
default	O
in	O
their	O
products	O
and	O
services	O
within	O
a	O
few	O
months	O
.	O
</s>
<s>
Microsoft	O
disabled	O
fallback	O
to	O
SSL	O
3.0	O
in	O
Internet	B-Application
Explorer	I-Application
11	O
for	O
Protect	O
Mode	O
sites	O
on	O
February	O
10	O
,	O
2015	O
,	O
and	O
for	O
other	O
sites	O
on	O
April	O
14	O
,	O
2015	O
.	O
</s>
<s>
Apple	B-Application
's	I-Application
Safari	I-Application
(	O
on	O
OS	O
X	O
10.8	O
,	O
iOS	O
8.1	O
and	O
later	O
)	O
mitigated	O
against	O
POODLE	B-Protocol
by	O
removing	O
support	O
for	O
all	O
CBC	O
protocols	O
in	O
SSL	O
3.0	O
,	O
however	O
,	O
this	O
left	O
RC4	O
which	O
is	O
also	O
completely	O
broken	O
by	O
the	O
RC4	O
attacks	O
in	O
SSL	O
0	O
..	O
POODLE	B-Protocol
was	O
completely	O
mitigated	O
in	O
OS	O
X	O
10.11	O
(	O
El	O
Capitan	O
2015	O
)	O
and	O
iOS	O
9	O
(	O
2015	O
)	O
.	O
</s>
<s>
To	O
prevent	O
the	O
POODLE	B-Protocol
attack	I-Protocol
,	O
some	O
web	O
services	O
dropped	O
support	O
of	O
SSL	O
3.0	O
.	O
</s>
<s>
Examples	O
include	O
CloudFlare	B-Application
and	O
Wikimedia	O
.	O
</s>
<s>
Network	B-Protocol
Security	I-Protocol
Services	I-Protocol
version	O
3.17.1	O
(	O
released	O
on	O
October	O
3	O
,	O
2014	O
)	O
and	O
3.16.2.3	O
(	O
released	O
on	O
October	O
27	O
,	O
2014	O
)	O
introduced	O
support	O
for	O
TLS_FALLBACK_SCSV	O
,	O
and	O
NSS	O
will	O
disable	O
SSL	O
3.0	O
by	O
default	O
in	O
April	O
2015	O
.	O
</s>
<s>
OpenSSL	B-Language
versions	O
1.0.1j	O
,	O
1.0.0o	O
and	O
0.9.8zc	O
,	O
released	O
on	O
October	O
15	O
,	O
2014	O
,	O
introduced	O
support	O
for	O
TLS_FALLBACK_SCSV	O
.	O
</s>
<s>
LibreSSL	B-Language
version	O
2.1.1	O
,	O
released	O
on	O
October	O
16	O
,	O
2014	O
,	O
disabled	O
SSL	O
3.0	O
by	O
default	O
.	O
</s>
<s>
A	O
new	O
variant	O
of	O
the	O
original	O
POODLE	B-Protocol
attack	I-Protocol
was	O
announced	O
on	O
December	O
8	O
,	O
2014	O
.	O
</s>
<s>
This	O
attack	O
exploits	O
implementation	O
flaws	O
of	O
CBC	O
encryption	O
mode	O
in	O
the	O
TLS	B-Protocol
1.0	O
-	O
1.2	O
protocols	O
.	O
</s>
<s>
Even	O
though	O
TLS	B-Protocol
specifications	O
require	O
servers	O
to	O
check	O
the	O
padding	O
,	O
some	O
implementations	O
fail	O
to	O
validate	O
it	O
properly	O
,	O
which	O
makes	O
some	O
servers	O
vulnerable	O
to	O
POODLE	B-Protocol
even	O
if	O
they	O
disable	O
SSL	O
3.0	O
.	O
</s>
<s>
SSL	O
Pulse	O
showed	O
"	O
about	O
10%	O
of	O
the	O
servers	O
are	O
vulnerable	O
to	O
the	O
POODLE	B-Protocol
attack	I-Protocol
against	O
TLS	B-Protocol
"	O
before	O
this	O
vulnerability	O
was	O
announced	O
.	O
</s>
<s>
The	O
entry	O
in	O
NIST	O
's	O
NVD	O
states	O
that	O
this	O
CVE-ID	O
is	O
to	O
be	O
used	O
only	O
for	O
F5	O
Networks	O
 '	O
implementation	O
of	O
TLS	B-Protocol
,	O
and	O
that	O
other	O
vendors	O
whose	O
products	O
have	O
the	O
same	O
failure	O
to	O
validate	O
the	O
padding	O
mistake	O
in	O
their	O
implementations	O
like	O
A10	O
Networks	O
and	O
Cisco	O
Systems	O
need	O
to	O
issue	O
their	O
own	O
CVE-IDs	O
for	O
their	O
implementation	O
errors	O
because	O
this	O
is	O
not	O
a	O
flaw	O
in	O
the	O
protocol	O
but	O
in	O
the	O
implementation	O
.	O
</s>
<s>
The	O
POODLE	B-Protocol
attack	I-Protocol
against	O
TLS	B-Protocol
was	O
found	O
to	O
be	O
easier	O
to	O
initiate	O
than	O
the	O
initial	O
POODLE	B-Protocol
attack	I-Protocol
against	O
SSL	O
.	O
</s>
