Re: [syslog-ng] Cisco ASA parsing with patterndb/elasticsearch

1 Mar 2018

      Can you give me a few inbound logs as received by syslog-ng? I would try to
fix up cisco parser that it works for your use-case, as it should.

Thanks

On Feb 28, 2018 21:48, "Tim Ghetti" <tghetti@targetedsupport.com> wrote:

I tried using the cisco-parser and not having any luck with that either.
When I enable the parser, I actually stop seeing outbound traffic to
elasticsearch. My config is below

log {

        source { udp(flags(no-parse)); };

        parser { cisco-parser(); };

        destination {

                elasticsearch2(

        client-mode("http")

                cluster("ITESCL001")

                index("logstash-syslogng_${YEAR}.${MONTH}.${DAY}")

                cluster-url("http://192.168.101.199:9200
http://192.168.101.198:9200")

                type("syslog")

                flush-limit("1"));

        };

}

[root@ITLOG001 conf.d]# tcpdump -nnSXi ens192 port 9200 -vv

tcpdump: listening on ens192, link-type EN10MB (Ethernet), capture size
262144 bytes

^C

0 packets captured

0 packets received by filter

0 packets dropped by kernel

*From:* syslog-ng [mailto:syslog-ng-bounces@lists.balabit.hu] *On Behalf Of
*Scheidler, Balázs
*Sent:* Tuesday, February 27, 2018 11:06 PM
*To:* Syslog-ng users' and developers' mailing list <
syslog-ng@lists.balabit.hu>

*Subject:* Re: [syslog-ng] Cisco ASA parsing with patterndb/elasticsearch

One additional feature you might be interested in is our cisco-parser()
feature.

It basically expects a flags(no-parse) input and then puts things in the
right buckets, while recognising the various formats that cisco uses.

It would be appreciated if you could check if it works with your setup and
I can help fixing it up if it doesn't.

The parser got added to recent syslog-ng versions, so you might need to
upgrade to a new version.

Bazsi

On Feb 27, 2018 22:29, "Tim Ghetti" <tghetti@targetedsupport.com> wrote:

Thanks!! It sounds like this is part of my problem. If you would be so kind
as to send an example (or point me in the right direction) of how you are
changing the program name and message body for the cisco logs that would be
extremely helpful.

I also suspect that there may be another issue. I’m almost certain that my
parser should be picking up at least some of the logs but I am not seeing
any of the fields in ES showing up based on parsed logs. Assuming that
patterndb is working, would the below config be correct for getting
patterndb parsed variables to show as fields in ES?

destination d_elastic {

    elasticsearch2(

        client-mode("http")

        cluster("ITESCL001")

        index("logstash-syslogng_${YEAR}.${MONTH}.${DAY}")

        cluster-url("http://X.X.X.X:9200")

        type("syslog")

        flush-limit("1")

    );

};

*From:* syslog-ng [mailto:syslog-ng-bounces@lists.balabit.hu] *On Behalf Of
*Evan Rempel
*Sent:* Tuesday, February 27, 2018 9:06 PM
*To:* syslog-ng@lists.balabit.hu
*Subject:* Re: [syslog-ng] Cisco ASA parsing with patterndb/elasticsearch

The program name will have an implied @ANYSTRING@ on the end, so if the
syslog payload could
be parsed to detect the program name of %ASA..... then your patterndb.xml
would work.
The problem is that they syslog payload can not be parsed.

What we do is use a hand crafted patterndb to detect all of the different
problem formats
that Cisco logs (in our environment) and change

a) the PROGRAM to be cisco_ASA or generally cisco_XXX where the XXX is the
leading characters of the %XXX-#-##### of the syslog body.
b) the MESSAGE to be %XXX-#-####... for the rest of the line.

All of the poor hosts, sequence numbers, timestamps etc are all thrown away.

After that, the internal buffers of syslog-ng contain a usable PROGRAM and
MESSAGE such that we can use
a patterndb to match the message part of the log line.

This does mean that we have two patterndb parsers for every log line but it
seems to work well for us.
What would work better is if Cisco would fix their logging, but that isn't
going to happen in my lifetime :-(

I hope that makes sense.

Evan.

On 02/27/2018 05:37 PM, Tim Ghetti wrote:

Ok, that makes sense. I sort of suspected that this was due to the program
name not matching, since pdbtool works when specifying the program name. Do
you know if there is a way to configure patterndb so that it matches the
program name, regardless of the full program name with event code? Is it
possible to regex the program or use the patterndb format i.e.
<pattern>%ASA@ANYSTRING::@</pattern> or something similar?

Tim

*From:* syslog-ng [mailto:syslog-ng-bounces@lists.balabit.hu
<syslog-ng-bounces@lists.balabit.hu>] *On Behalf Of *Evan Rempel
*Sent:* Tuesday, February 27, 2018 8:26 PM
*To:* syslog-ng@lists.balabit.hu
*Subject:* Re: [syslog-ng] Cisco ASA parsing with patterndb/elasticsearch

Welcome to the horrible world of Cisco logging :-(

The issue you are bumping into is that when these log lines are parsed by
syslog-ng (or any
syslog daemon that does not specifically understand Cisco logs) there is no
program name, or the
program name is the full %ASA-4-106023 part of the log line. There are so
many ways that Cisco
can log incorrectly it is not possible to say without seeing your exact log
lines.

Cisco can add a * to the date/time stamp to indicate that there is no time
server configured on the device.
That makes the date/time invalid as far as parsing is concerned.

Cisco can add a period (.) to the date/time stamp to indicate that there is
a time server configured on
the device, but the time server can not be reached. Again, this makes the
date/time invalid as far as parsing
is concerned.

Cisco can add a sequence number at the start of the log line rather than
starting the line with a date/6time stamp.
Invalid parsing again.

Cisco can leave out the sequence number but still include the trailing
colon from the sequence number.

You get the idea. So many ways to get it wrong, and they never get it right
:-(

Evan.

On 02/27/2018 04:46 PM, Tim Ghetti wrote:

Hi – having some trouble getting paterndb functional and looking for some
help. I would like to use patterndb to parse my cisco ass firewall logs
before sending it to elasticsearch. However when the messages get to
elasticsearch, I don’t see the messages being parsed. Running  pdbtool
against the logs seems to work.

# pdbtool match -p /etc/syslog-ng/patterndb.d/ciscoasa.pdb -P %ASA -f
/var/log/asatest.log |more

HOST=X.X.X.X

MESSAGE=Built dynamic TCP translation from INSIDE:X.X.X.X/X to
OUTSIDE:X.X.X.X/X

PROGRAM=%ASA-6-305011

LEGACY_MSGHDR=%ASA-6-305011:

.classifier.class=system

.classifier.rule_id=e075efdc-c25f-5e49-a208-7661e3b5a29b

Protocol=TCP

GlobalIP=X.X.X.X

GlobalPort=X

LocalIP=X.X.X.X

LocalPort=X

TAGS=.classifier.system

**********************

SYSLOG-NG CONF FILE

@version: 3.11

source s_network { tcp(); udp(); };

destination d_elastic {

    elasticsearch2(

        client-mode("http")

        cluster("ITESCL001")

        index("logstash-syslogng_${YEAR}.${MONTH}.${DAY}")

        cluster-url("http://X.X.X.X:9200")

        type("syslog")

        flush-limit("1")

    );

};

destination d_catchall { file("/var/log/catchall.log"); };

filter f_ciscoasa { host("X.X.X.X"); };

parser p_ciscoasa {db-parser(file("/etc/syslog-
ng/patterndb.d/ciscoasa.pdb"));};

log { source(s_network); filter(f_ciscoasa); parser(p_ciscoasa);
destination(d_elastic); flags(final, flow-control); };

log { source(s_network); destination(d_catchall); };

**********************

PATTERNDB FILE

<?xml version='1.0' encoding='UTF-8'?>

<patterndb version='4' pub_date='2018-02-19'>

  <ruleset name='%ASA' id='a300d776-8bd7-834d-a4a9-23eb81a4b3ba'>

  <pattern>%ASA</pattern>

  <description>

    This ruleset covers the Cisco ASA firewalls

  </description>

    <rules>

      <rule provider="%ASA" id="b3de7699-8213-c744-944e-9413298afe86"
class="system">

        <!-- support: 1594 -->

        <patterns>

          <pattern>Teardown @ESTRING:Protocol: @connection for faddr
@IPv4:SrcIP:/@@ESTRING:SrcPort: @gaddr @IPv4:GlobalIP:/@@ESTRING:GlobalPort:
@laddr @IPv4:LocalIP:/@@ESTRING:LocalPort:@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Teardown ICMP connection for
faddr X.X.X.X/X gaddr X.X.X.X/X laddr X.X.X.X/X</test_message>

            </example>

        </examples>

      </rule>

      <rule id='90d0f8c9-7591-d44e-b886-2f7e5cb17ce6' class='system'
provider='%ASA'>

        <!-- support: 1369 -->

        <patterns>

          <pattern>Teardown dynamic @ESTRING:Protocol: @translation from
@ESTRING:::@@IPv4:LocalIP:/@@ESTRING:LocalPort: @to @ESTRING:::@
@IPv4:GlobalIP:/@@ESTRING:GlobalPort: @duration@ANYSTRING::@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Teardown dynamic UDP
translation from any:X.X.X.X/X to outside:X.X.X.X/X duration
0:00:00</test_message>

            </example>

        </examples>

      </rule>

      <rule id='8f0a8d57-80c6-4745-8a8a-5ce018bb0d87' class='system'
provider='%ASA'>

        <!-- support: 1254 -->

        <patterns>

          <pattern>Teardown @ESTRING:Protocol: @connection @ESTRING:: @for
@ESTRING:::@@IPv4:DstIP:/@@ESTRING:DstPort: @to
@ESTRING:::@@IPv4:SrcIP:/@@ESTRING:SrcPort:
@@ESTRING::@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Teardown UDP connection
55101037 <(55)%20101%20037> for outside:X.X.X.X/X to inside:X.X.X.X/X
duration 0:00:00 bytes 132</test_message>

            </example>

        </examples>

      </rule>

      <rule id='00c0732d-1e34-7340-a75f-21198bf71137' class='system'
provider='%ASA'>

        <!-- support: 1256 -->

        <patterns>

          <pattern>Built outbound @ESTRING:Protocol: @connection @ESTRING::
@for @ESTRING:::@@IPv4:DstIP:/@@ESTRING:DstPort: @(@ESTRING::)@ to
@ESTRING:::@@IPv4:SrcIP:/@@ESTRING:SrcPort: @(@ESTRING::)@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Built outbound UDP connection
55101037 <(55)%20101%20037> for outside:X.X.X.X/X (X.X.X.X/X) to
inside:X.X.X.X/X (X.X.X.X/X)</test_message>

            </example>

        </examples>

      </rule>

      <rule id='4a586711-ebe2-dc4d-bf6e-e512666d8c5d' class='system'
provider='%ASA'>

        <!-- support: 1594 -->

        <patterns>

          <pattern>Built inbound @ESTRING:Protocol: @connection for faddr
@IPv4:SrcIP:/@@ESTRING:SrcPort: @gaddr @IPv4:GlobalIP:/@@ESTRING:GlobalPort:
@laddr @IPv4:LocalIP:/@@ESTRING:LocalPort:@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Built inbound ICMP connection
for faddr X.X.X.X/X gaddr X.X.X.X/X laddr X.X.X.X/X</test_message>

            </example>

        </examples>

      </rule>

      <rule id='8be7928d-66e7-7042-abd5-869d6b49c56e' class='system'
provider='%ASA'>

        <!-- support: 1763 -->

        <patterns>

          <pattern>Built inbound @ESTRING:Protocol: @connection @ESTRING::
@for @ESTRING::@@IPv4:SrcIP:/@@ESTRING:SrcPort: @(@ESTRING::)@ to
identity:@IPv4:DstIP:/@@ESTRING:DstPort: @(@ESTRING::)@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Built inbound UDP connection
55101078 <(55)%20101%20078> for inside:X.X.X.X/X (X.X.X.X/X) to
identity:X.X.X.X/X (X.X.X.X/X)</test_message>

            </example>

        </examples>

      </rule>

      <rule id='20aee256-b4f0-8b4d-93cb-263d5338fd21' class='system'
provider='%ASA'>

        <!-- support: 1539 -->

        <patterns>

          <pattern>Teardown @ESTRING:Protocol: @connection @ESTRING:: @for
@ESTRING:::@@IPv4:SrcIP:/@@ESTRING:SrcPort: @to
identity:@IPv4:DstIP:/@@ESTRING:DstPort:
@duration@ANYSTRING::@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Teardown UDP connection
55101084 <(55)%20101%20084> for inside:X.X.X.X/X to identity:X.X.X.X/X
duration 0:02:01 bytes 88</test_message>

            </example>

        </examples>

      </rule>

      <rule id='e075efdc-c25f-5e49-a208-7661e3b5a29b' class='system'
provider='%ASA'>

        <!-- support: 3648 -->

        <patterns>

          <pattern>Built dynamic @ESTRING:Protocol: @translation from
@ESTRING:::@@IPv4:LocalIP:/@@ESTRING:LocalPort: @to @ESTRING:::@
@IPv4:GlobalIP:/@@ESTRING:GlobalPort:@</pattern>

        </patterns>

        <examples>

            <example>

                <test_message program='%ASA'>Built dynamic TCP translation
from any:X.X.X.X/X to outside:X.X.X.X/X</test_message>

            </example>

        </examples>

      </rule>

      <rule provider='%ASA' class='system' id='39'>

        <patterns>

          <pattern>Cleared @ESTRING:: @urgent flag from @ESTRING:::@
@ESTRING::/@@NUMBER::@ to @ESTRING: ::@@ESTRING::/@@NUMBER::@</pattern>

          <pattern>regular translation creation failed for @ESTRING:: @src
@ESTRING:::@@ESTRING:: @dst @ESTRING: ::@@ESTRING:: @(type @NUMBER::@, code
@NUMBER::@</pattern>

        </patterns>

      </rule>

    </rules>

  </ruleset>

</patterndb>

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Scheidler, Balázs

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