Bug #8864: SSH Guard Sensitivity/Whitelist on 2.4.4 - pfSense - pfSense bugtracker

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Bug #8864

closed

SSH Guard Sensitivity/Whitelist on 2.4.4

Added by Zachary McGibbon over 6 years ago. Updated about 6 years ago.

Status:

Resolved

Priority:

Normal

Assignee:

Renato Botelho

Category:

Target version:

2.4.4-p1

Start date:

08/31/2018

Due date:

% Done:

100%

Estimated time:

Plus Target Version:

Release Notes:

Affected Version:

2.4.4

Affected Architecture:

All

Description

I am running 2.4.4.a.20180831.0830 and noticed that my Icinga monitoring started to show issues with SSH. When I looked in the logs I saw the following:

Aug 31 17:04:09 sshguard 39986 Attack from "192.168.0.2" on service 100 with danger 10.

Is this a new feature and if so how do I tune it to allow my Icinga server to check SSH?

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Updated by Zachary McGibbon over 6 years ago

Sorry I meant to put 2.4.4.a.20180831.0830 in the topic after 'SSH Guard on 2.4.4.a.20180831.0830'

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Updated by Anonymous over 6 years ago

Subject changed from SSH Guard on to SSH Guard on 2.4.4.a.20180831.0830

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Updated by Nicki Messerschmidt over 6 years ago

I just want to chime in on this. I just updated my pfsense to 2.4.4 and very soon after I got notifications from my nagios system. Is there any way to whitelist IPs?

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Updated by Jim Pingle over 6 years ago

Subject changed from SSH Guard on 2.4.4.a.20180831.0830 to SSH Guard Sensitivity/Whitelist on 2.4.4
Target version set to 2.4.4-GS
Affected Architecture All added
Affected Architecture deleted ()

There isn't a way to set a whitelist currently. But if your monitoring system relies on a probe that is triggering an alert, that sounds more like a problem in the monitoring system.

I sent maybe 100 probes immediately to a 2.4.4 box with that only tested the TCP port and it never triggered sshguard. I then sent a handful that caused a login failure and it tripped after only three attempts.

If your ssh test is actually causing a login failure, try changing it to one that does a simple TCP handshake instead of checking the banner or whatever else it's doing.

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Updated by Nicki Messerschmidt over 6 years ago

Well... I'm using the default check_ssh plugin of nagios. This plugin connects to the ssh server and checks before authentication if there really is a ssh server responding and what version number is reported. That in intself should not trigger an alarm. The corresponding logfile on the pfsense looks like this:

pfsense sshd[xxxxx]: Connection closed by xxx.xxx.xxx.xxx port 45345 [preauth]

According to the sshguard website whitelisting is possible using single IPs or using a whitelist file.

At least give the option of restarting/disabling sshguard via the interface. Right now it is a process that interferes with normal operations in a way pfsense did not before and there is no way to control this behaviour.

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Updated by Alexander Müller over 6 years ago

I found following workaround:

create whitelist file for sshguard following sshguards file format (https://www.sshguard.net/docs/whitelist/). put the file somewhere in the filesystem

adjust /etc/inc/system.inc / line 1062:

auth.info;authpriv.info  |exec /usr/local/sbin/sshguard -w $fullPathToYourWhitelist

Navigate to Status > System Logs > Manage Logs and save without any changes

Would be really cool to have a proper configuration function in the webConfigurator. My monitoring systems (icinga2) gets blocked during ssh probes

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Updated by Michael Reardon about 6 years ago

Alexander Müller wrote:

I found following workaround:

create whitelist file for sshguard following sshguards file format (https://www.sshguard.net/docs/whitelist/). put the file somewhere in the filesystem

adjust /etc/inc/system.inc / line 1062:
[...]

Navigate to Status > System Logs > Manage Logs and save without any changes

Would be really cool to have a proper configuration function in the webConfigurator. My monitoring systems (icinga2) gets blocked during ssh probes

Thanks! This seems to be working well enough for me for the time being.

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