On Thu, Mar 7, 2013 at 7:38 AM, Jean-Pierre Zurbrugg
<[email protected]> wrote:
> Hello Jb,
>
> Yeah I have noticed too; It initially led me to believe the comma was more
> of a good practice than a requirement but I removed it from
> rules/firewall_rules.xml, commented out the no log option on rule 4101, and
> confirmed that the comma was indeed needed.
>
> Anyways, I've stumbled upon another issue that I hope isn't me screwing up
> again. I've been trying to make some firewall rules work ever since I
> started this thread and couldn't get the Alerts to show up on
> /var/ossec/logs/alerts/alerts.log. ossec-logtest would report everything
> triggered correctly but no alerts were being sent to the alerts.log file.
>
> It all points to the same firewall rule, 4101 inside
> rules/firewall_rules.xml.
>
> Steps to recreate my issue:
> 1. Edit rules/firewall_rules.xml on your lab environment. Comment out
> "<options>no_log</options>"

That's a bad way to go about it. I tested this by recreating the rule
in local_rules.xml and adding the overwrite option.

> 2. Save, restart OSSEC and send the following log to /var/log/messages or
> syslog:
>
> Mar  6 16:17:47 ubuntu kernel: [546741.275556] DROP IN=eth1 OUT=
> MAC=00:00:20:57:10:41:08:00:f3:0b:80:40:00:00 SRC=1.1.1.1 DST=2.2.2.2 LEN=48
> TOS=0x00 PREC=0x00 TTL=127 ID=11702 DF PROTO=TCP SPT=16966 DPT=80
> WINDOW=8192 RES=0x00 SYN URGP=0
>
> 3. Confirm you get the firewall log at /var/ossec/logs/alerts/alerts.
> ...all good so far.
> 4. Update rule 4101 inside rules/firewall_rules.xml again, this time remove
> "DROP" and type in "TEST".  OSSEC's iptables decoder will still tag test as
> an action.
> 5. send out this log:
>
> Mar  6 16:17:47 ubuntu kernel: [546741.275556] TEST IN=eth1 OUT=
> MAC=00:00:20:57:10:41:08:00:f3:0b:80:40:00:00 SRC=1.1.1.1 DST=2.2.2.2 LEN=48
> TOS=0x00 PREC=0x00 TTL=127 ID=11702 DF PROTO=TCP SPT=16966 DPT=80
> WINDOW=8192 RES=0x00 SYN URGP=0
>
> 6. Notice how no logs are sent to /var/ossec/alerts/alerts.log
> *** /var/ossec/logs/firewall/firewall.log gets populated with a new entry:
> 2013 Mar 07 08:17:59 ubuntu->/var/log/messages CLOSED TCP
> 1.1.1.1:16966->2.2.2.2:80
> END.
>

I see the same thing, no idea why. Instead of breaking rule 4101 I
created a new rule looking for TEST. It's possible there's something
in the firewall code path making this happen. Before I consider
digging into it, what's the real world application of the TEST action?
Is it worth caring about? (I'd suspect you'd need to mess with
src/analysis/alerts/log.c, specifically the case after "    /* Setting
the actions */")

> Tested on version 2.7 (server mode) under ubuntu 10.04.3 LTS. No
> local_decoders and no local_rules(dummy rule inside).
>
>
> Thanks in advance,
>
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