<s>
ModSecurity	B-Language
,	O
sometimes	O
called	O
Modsec	O
,	O
is	O
an	O
open-source	B-Application
web	B-Protocol
application	I-Protocol
firewall	I-Protocol
(	O
WAF	O
)	O
.	O
</s>
<s>
Originally	O
designed	O
as	O
a	O
module	O
for	O
the	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
,	O
it	O
has	O
evolved	O
to	O
provide	O
an	O
array	O
of	O
Hypertext	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
request	O
and	O
response	O
filtering	O
capabilities	O
along	O
with	O
other	O
security	O
features	O
across	O
a	O
number	O
of	O
different	O
platforms	O
including	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
,	O
Microsoft	B-Application
IIS	I-Application
and	O
Nginx	B-Operating_System
.	O
</s>
<s>
It	O
is	O
a	O
free	B-Application
software	I-Application
released	O
under	O
the	O
Apache	B-Application
license	I-Application
2.0	O
.	O
</s>
<s>
The	O
platform	O
provides	O
a	O
rule	O
configuration	O
language	O
known	O
as	O
'	O
SecRules	O
 '	O
for	O
real-time	O
monitoring	O
,	O
logging	O
,	O
and	O
filtering	O
of	O
Hypertext	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
communications	O
based	O
on	O
user-defined	O
rules	O
.	O
</s>
<s>
Although	O
not	O
its	O
only	O
configuration	O
,	O
ModSecurity	B-Language
is	O
most	O
commonly	O
deployed	O
to	O
provide	O
protections	O
against	O
generic	O
classes	O
of	O
vulnerabilities	O
using	O
the	O
OWASP	O
ModSecurity	B-Language
Core	O
Rule	O
Set	O
(	O
CRS	O
)	O
.	O
</s>
<s>
This	O
is	O
an	O
open-source	B-Application
set	O
of	O
rules	O
written	O
in	O
ModSecurity	B-Language
's	O
SecRules	O
language	O
.	O
</s>
<s>
To	O
detect	O
threats	O
,	O
the	O
ModSecurity	B-Language
engine	O
is	O
deployed	O
embedded	O
within	O
the	O
webserver	O
or	O
as	O
a	O
proxy	O
server	O
in	O
front	O
of	O
a	O
web	O
application	O
.	O
</s>
<s>
This	O
allows	O
the	O
engine	O
to	O
scan	O
incoming	O
and	O
outgoing	O
HTTP	B-Protocol
communications	O
to	O
the	O
endpoint	O
.	O
</s>
<s>
ModSecurity	B-Language
was	O
first	O
developed	O
by	O
Ivan	O
Ristić	O
,	O
who	O
wrote	O
the	O
module	O
with	O
the	O
end	O
goal	O
of	O
monitoring	O
application	O
traffic	O
on	O
the	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
.	O
</s>
<s>
The	O
first	O
version	O
was	O
released	O
in	O
November	O
2002	O
which	O
supported	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
1.3.x	O
.	O
</s>
<s>
Shortly	O
after	O
Ivan	O
's	O
departure	O
from	O
Breach	O
Security	O
,	O
Trustwave	O
Holdings	O
acquired	O
Breach	O
in	O
June	O
2010	O
and	O
relicensed	O
ModSecurity	B-Language
under	O
the	O
Apache	B-Application
license	I-Application
.	O
</s>
<s>
Development	O
continued	O
and	O
the	O
new	O
license	O
allowed	O
easier	O
integration	O
of	O
ModSecurity	B-Language
into	O
other	O
products	O
.	O
</s>
<s>
As	O
a	O
result	O
of	O
this	O
there	O
was	O
steady	O
adoption	O
of	O
ModSecurity	B-Language
by	O
various	O
commercial	O
products	O
.	O
</s>
<s>
Hence	O
,	O
Microsoft	O
contributed	O
an	O
IIS	B-Application
port	O
in	O
August	O
2012	O
and	O
the	O
port	O
for	O
Nginx	B-Operating_System
was	O
released	O
at	O
Black	O
Hat	O
Briefings	O
in	O
2012	O
.	O
</s>
<s>
It	O
covers	O
ModSecurity	B-Language
up	O
to	O
version	O
2.9.2	O
.	O
</s>
<s>
Being	O
originally	O
an	O
Apache	B-Application
module	O
,	O
porting	O
ModSecurity	B-Language
to	O
other	O
platforms	O
was	O
time-consuming	O
and	O
had	O
high	O
maintenance	O
costs	O
.	O
</s>
<s>
This	O
new	O
iteration	O
,	O
libmodsecurity	O
,	O
changes	O
the	O
underlying	O
architecture	O
,	O
separating	O
ModSecurity	B-Language
into	O
a	O
standalone	O
engine	O
that	O
communicates	O
with	O
the	O
web	O
server	O
via	O
an	O
API	O
.	O
</s>
<s>
This	O
modular	O
architecture-based	O
WAF	O
,	O
which	O
was	O
announced	O
for	O
public	O
use	O
in	O
January	O
2018	O
,	O
became	O
libmodsecurity	O
(	O
ModSecurity	B-Language
version	O
3.0	O
)	O
and	O
has	O
supported	O
connectors	O
for	O
Nginx	B-Operating_System
and	O
Apache	B-Application
.	O
</s>
<s>
In	O
2021	O
,	O
Trustwave	O
Holdings	O
,	O
announce	O
the	O
End-of-Sale	O
(	O
EOS	O
)	O
of	O
Trustwave	O
support	O
for	O
ModSecurity	B-Language
effective	O
August	O
1	O
,	O
2021	O
and	O
the	O
End-of-Life	O
(	O
EOL	O
)	O
of	O
support	O
effective	O
July	O
1	O
,	O
2024	O
.	O
</s>
<s>
The	O
maintenance	O
of	O
the	O
ModSecurity	B-Language
code	O
is	O
given	O
to	O
the	O
open-source	B-Application
community	O
.	O
</s>
<s>
The	O
default	O
rules	O
shipped	O
with	O
most	O
ModSecurity	B-Language
distributions	O
are	O
the	O
OWASP	O
ModSecurity	B-Language
Core	O
Rule	O
Set	O
(	O
CRS	O
)	O
.	O
</s>
<s>
These	O
rules	O
used	O
to	O
block	O
the	O
Lynx	B-Application
browser	I-Application
as	O
an	O
"	O
automated	O
tool	O
"	O
,	O
returning	O
a	O
"	O
406	O
Not	O
Acceptable	O
"	O
to	O
it	O
unless	O
its	O
user-agent	O
string	O
was	O
changed	O
.	O
</s>
<s>
This	O
inconvenienced	O
users	O
with	O
blindness	O
who	O
work	O
in	O
Lynx	B-Application
.	O
</s>
<s>
However	O
,	O
with	O
the	O
release	O
of	O
Core	O
Rule	O
Set	O
3.0	O
(	O
CRS3	O
)	O
,	O
a	O
Lynx	B-Application
user	O
agent	O
does	O
not	O
trigger	O
any	O
rules	O
anymore	O
.	O
</s>
