Well, correct me if I'm wrong, but I would say this conversation you have posted is a bit outdated, now fail2ban can be used with asterisk security log https://wiki.asterisk.org/wiki/display/AST/Asterisk+Security+Event+Logger. On Thu, Aug 17, 2017, 4:53 AM Telium Technical Support <support at telium.ca> wrote:> Keep in mind that the attacks you are seeing in the log are ONLY the ones > that Asterisk is detecting and rejecting. All other attacks aren't even > showing up! > > There's a good discussion of how to secure your PBX here: > https://www.voip-info.org/wiki/view/asterisk+security > > In general, don't let the malevolent traffic get as far as the PBX (block > at > the firewall). Also, Digium regularly warns users that fail2ban is NOT a > security system: http://forums.asterisk.org/viewtopic.php?p=159984 > > -----Original Message----- > From: asterisk-users-bounces at lists.digium.com > [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of mdiehl > Sent: Tuesday, August 15, 2017 3:38 PM > To: asterisk-users at lists.digium.com > Subject: [asterisk-users] Detecting DoS attacks via SIP > > Hi all, > > Lately, I've seen an increase in the number of attacks against my system > from the so-called "Friendly Scanner." When one of these script kiddies > targets my server, all I see for symptoms is a few of my trunks become > lagged due to server load and a stream of messages on the console that > resemble this: > > [Aug 2 20:27:50] == Using SIP VIDEO CoS mark 6 > [Aug 2 20:27:50] == Using SIP RTP TOS bits 24 > [Aug 2 20:27:50] == Using SIP RTP CoS mark 5 > [Aug 2 20:32:47] == Using SIP VIDEO TOS bits 24 > [Aug 2 20:32:47] == Using SIP VIDEO CoS mark 6 > [Aug 2 20:32:47] == Using SIP RTP TOS bits 24 > [Aug 2 20:32:47] == Using SIP RTP CoS mark 5 > [Aug 2 20:34:26] == Using SIP VIDEO TOS bits 24 > [Aug 2 20:34:26] == Using SIP VIDEO CoS mark 6 > > > I have to turn on sip debugging to find out who's hitting me. However, I > can't just leave it on because it would kill my logging system. > > So, how are other people handling this? Is there an AMI event I want watch > for? I watch for PeerStatus, but since there's no actual peer in the > attack, I don't seem to get an event from AMI. > > Any ideas? > > Mike Diehl. > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: > https://community.asterisk.org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: > https://community.asterisk.org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20170817/59bf8199/attachment.html>
I shall recommend fail2ban. We have been using fail2ban successfully for our Asterisk servers (Debian). Help on using fail2ban with Asterisk server: https://www.voip-info.org/wiki/view/Fail2Ban+%28with+iptables%29+And+Asterisk On Thu, Aug 17, 2017 at 10:10 AM, Kseniya Blashchuk <ksyblast at gmail.com> wrote:> Well, correct me if I'm wrong, but I would say this conversation you have > posted is a bit outdated, now fail2ban can be used with asterisk security > log > https://wiki.asterisk.org/wiki/display/AST/Asterisk+Security+Event+Logger. > > > On Thu, Aug 17, 2017, 4:53 AM Telium Technical Support <support at telium.ca> > wrote: >> >> Keep in mind that the attacks you are seeing in the log are ONLY the ones >> that Asterisk is detecting and rejecting. All other attacks aren't even >> showing up! >> >> There's a good discussion of how to secure your PBX here: >> https://www.voip-info.org/wiki/view/asterisk+security >> >> In general, don't let the malevolent traffic get as far as the PBX (block >> at >> the firewall). Also, Digium regularly warns users that fail2ban is NOT a >> security system: http://forums.asterisk.org/viewtopic.php?p=159984 >> >> -----Original Message----- >> From: asterisk-users-bounces at lists.digium.com >> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of mdiehl >> Sent: Tuesday, August 15, 2017 3:38 PM >> To: asterisk-users at lists.digium.com >> Subject: [asterisk-users] Detecting DoS attacks via SIP >> >> Hi all, >> >> Lately, I've seen an increase in the number of attacks against my system >> from the so-called "Friendly Scanner." When one of these script kiddies >> targets my server, all I see for symptoms is a few of my trunks become >> lagged due to server load and a stream of messages on the console that >> resemble this: >> >> [Aug 2 20:27:50] == Using SIP VIDEO CoS mark 6 >> [Aug 2 20:27:50] == Using SIP RTP TOS bits 24 >> [Aug 2 20:27:50] == Using SIP RTP CoS mark 5 >> [Aug 2 20:32:47] == Using SIP VIDEO TOS bits 24 >> [Aug 2 20:32:47] == Using SIP VIDEO CoS mark 6 >> [Aug 2 20:32:47] == Using SIP RTP TOS bits 24 >> [Aug 2 20:32:47] == Using SIP RTP CoS mark 5 >> [Aug 2 20:34:26] == Using SIP VIDEO TOS bits 24 >> [Aug 2 20:34:26] == Using SIP VIDEO CoS mark 6 >> >> >> I have to turn on sip debugging to find out who's hitting me. However, I >> can't just leave it on because it would kill my logging system. >> >> So, how are other people handling this? Is there an AMI event I want >> watch >> for? I watch for PeerStatus, but since there's no actual peer in the >> attack, I don't seem to get an event from AMI. >> >> Any ideas? >> >> Mike Diehl. >> >> -- >> _____________________________________________________________________ >> -- Bandwidth and Colocation Provided by http://www.api-digital.com -- >> >> Check out the new Asterisk community forum at: >> https://community.asterisk.org/ >> >> New to Asterisk? Start here: >> https://wiki.asterisk.org/wiki/display/AST/Getting+Started >> >> asterisk-users mailing list >> To UNSUBSCRIBE or update options visit: >> http://lists.digium.com/mailman/listinfo/asterisk-users >> >> >> -- >> _____________________________________________________________________ >> -- Bandwidth and Colocation Provided by http://www.api-digital.com -- >> >> Check out the new Asterisk community forum at: >> https://community.asterisk.org/ >> >> New to Asterisk? Start here: >> https://wiki.asterisk.org/wiki/display/AST/Getting+Started >> >> asterisk-users mailing list >> To UNSUBSCRIBE or update options visit: >> http://lists.digium.com/mailman/listinfo/asterisk-users > > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: > https://community.asterisk.org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users-- Regards, Tirveni Yadav www.bael.io What is this Universe ? From what it arises ? Into what does it go? In freedom it arises, In freedom it rests and into freedom it melts away. Upanishads. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20170817/66c36288/attachment.html>
Telium Technical Support
2017-Aug-19 20:36 UTC
[asterisk-users] Detecting DoS attacks via SIP
I think you missed the point of the Digium post. Fail2ban can ONLY ban IP?s if
Asterisk records a failure to register. Asterisk does not detect malformed SIP
packets, buffer overflow attacks, suspicious dialing patterns, connection
attempts outside geofenced areas, use of stolen credentials (rapid ramp of
calls using one set of credentials), etc.
Asterisk only gives you a rudimentary ?failed? message for a failure to register
/ wrong credentials. And of course fail2ban only responds to Asterisk log
messages, so it does little more than ban the annoying script kiddies.
Have a good look at that Voip-Info page and read what actual SIP security
systems do. Then compare that to fail2ban and it?s night & day difference.
People still think fail2ban is a security system, and Digium is very clear that
it is NOT.
From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces
at lists.digium.com] On Behalf Of Kseniya Blashchuk
Sent: Thursday, August 17, 2017 12:41 AM
To: Asterisk Users Mailing List - Non-Commercial Discussion <asterisk-users
at lists.digium.com>
Subject: Re: [asterisk-users] Detecting DoS attacks via SIP
Well, correct me if I'm wrong, but I would say this conversation you have
posted is a bit outdated, now fail2ban can be used with asterisk security log
https://wiki.asterisk.org/wiki/display/AST/Asterisk+Security+Event+Logger.
On Thu, Aug 17, 2017, 4:53 AM Telium Technical Support <support at telium.ca
<mailto:support at telium.ca> > wrote:
Keep in mind that the attacks you are seeing in the log are ONLY the ones
that Asterisk is detecting and rejecting. All other attacks aren't even
showing up!
There's a good discussion of how to secure your PBX here:
https://www.voip-info.org/wiki/view/asterisk+security
In general, don't let the malevolent traffic get as far as the PBX (block at
the firewall). Also, Digium regularly warns users that fail2ban is NOT a
security system: http://forums.asterisk.org/viewtopic.php?p=159984
-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
<mailto:asterisk-users-bounces at lists.digium.com>
[mailto:asterisk-users-bounces at lists.digium.com
<mailto:asterisk-users-bounces at lists.digium.com> ] On Behalf Of mdiehl
Sent: Tuesday, August 15, 2017 3:38 PM
To: asterisk-users at lists.digium.com <mailto:asterisk-users at
lists.digium.com>
Subject: [asterisk-users] Detecting DoS attacks via SIP
Hi all,
Lately, I've seen an increase in the number of attacks against my system
from the so-called "Friendly Scanner." When one of these script
kiddies
targets my server, all I see for symptoms is a few of my trunks become
lagged due to server load and a stream of messages on the console that
resemble this:
[Aug 2 20:27:50] == Using SIP VIDEO CoS mark 6
[Aug 2 20:27:50] == Using SIP RTP TOS bits 24
[Aug 2 20:27:50] == Using SIP RTP CoS mark 5
[Aug 2 20:32:47] == Using SIP VIDEO TOS bits 24
[Aug 2 20:32:47] == Using SIP VIDEO CoS mark 6
[Aug 2 20:32:47] == Using SIP RTP TOS bits 24
[Aug 2 20:32:47] == Using SIP RTP CoS mark 5
[Aug 2 20:34:26] == Using SIP VIDEO TOS bits 24
[Aug 2 20:34:26] == Using SIP VIDEO CoS mark 6
I have to turn on sip debugging to find out who's hitting me. However, I
can't just leave it on because it would kill my logging system.
So, how are other people handling this? Is there an AMI event I want watch
for? I watch for PeerStatus, but since there's no actual peer in the
attack, I don't seem to get an event from AMI.
Any ideas?
Mike Diehl.
--
_____________________________________________________________________
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
Check out the new Asterisk community forum at:
https://community.asterisk.org/
New to Asterisk? Start here:
https://wiki.asterisk.org/wiki/display/AST/Getting+Started
asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
http://lists.digium.com/mailman/listinfo/asterisk-users
--
_____________________________________________________________________
-- Bandwidth and Colocation Provided by http://www.api-digital.com --
Check out the new Asterisk community forum at: https://community.asterisk.org/
New to Asterisk? Start here:
https://wiki.asterisk.org/wiki/display/AST/Getting+Started
asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
http://lists.digium.com/mailman/listinfo/asterisk-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.digium.com/pipermail/asterisk-users/attachments/20170819/bfb7c900/attachment.html>
I appreciate the discussion on the question I asked. I currently listen for failed registration attempts via AMI and automatically block the offending IP address at the firewall. I was hoping to find another AMI event that would be the magic bullet I need, but it doesn't sound like that's going to happen. I understand that fail2ban is probably not what I want and probably wouldn't detect the attacks I'm seeing. It turns out that not all of the attacks are from the "friendly scanner," but enough of them are that it's a good start. So, I really like the idea of the IP geo location firewall rules coupled with the "friendly scanner" filter, as provided by a few of you guys. It was mentioned that this is a broad hammer, but I'm kinda looking for a broad hammer! ;^) Looks like I need to do some research, but I think I have what I need. Thanks again, Mike Diehl. On Sat, Aug 19, 2017 at 4:36 PM, Telium Technical Support <support at telium.ca> wrote:> I think you missed the point of the Digium post. Fail2ban can ONLY ban > IP?s if Asterisk records a failure to register. Asterisk does not detect > malformed SIP packets, buffer overflow attacks, suspicious dialing > patterns, connection attempts outside geofenced areas, use of stolen > credentials (rapid ramp of calls using one set of credentials), etc. > > > > Asterisk only gives you a rudimentary ?failed? message for a failure to > register / wrong credentials. And of course fail2ban only responds to > Asterisk log messages, so it does little more than ban the annoying script > kiddies. > > > > Have a good look at that Voip-Info page and read what actual SIP security > systems do. Then compare that to fail2ban and it?s night & day > difference. People still think fail2ban is a security system, and Digium > is very clear that it is NOT. > > > > > > *From:* asterisk-users-bounces at lists.digium.com [mailto:asterisk-users- > bounces at lists.digium.com] *On Behalf Of *Kseniya Blashchuk > *Sent:* Thursday, August 17, 2017 12:41 AM > *To:* Asterisk Users Mailing List - Non-Commercial Discussion < > asterisk-users at lists.digium.com> > *Subject:* Re: [asterisk-users] Detecting DoS attacks via SIP > > > > Well, correct me if I'm wrong, but I would say this conversation you have > posted is a bit outdated, now fail2ban can be used with asterisk security > log https://wiki.asterisk.org/wiki/display/AST/Asterisk+ > Security+Event+Logger. > > > > On Thu, Aug 17, 2017, 4:53 AM Telium Technical Support <support at telium.ca> > wrote: > > Keep in mind that the attacks you are seeing in the log are ONLY the ones > that Asterisk is detecting and rejecting. All other attacks aren't even > showing up! > > There's a good discussion of how to secure your PBX here: > https://www.voip-info.org/wiki/view/asterisk+security > > In general, don't let the malevolent traffic get as far as the PBX (block > at > the firewall). Also, Digium regularly warns users that fail2ban is NOT a > security system: http://forums.asterisk.org/viewtopic.php?p=159984 > > -----Original Message----- > From: asterisk-users-bounces at lists.digium.com > [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of mdiehl > Sent: Tuesday, August 15, 2017 3:38 PM > To: asterisk-users at lists.digium.com > Subject: [asterisk-users] Detecting DoS attacks via SIP > > Hi all, > > Lately, I've seen an increase in the number of attacks against my system > from the so-called "Friendly Scanner." When one of these script kiddies > targets my server, all I see for symptoms is a few of my trunks become > lagged due to server load and a stream of messages on the console that > resemble this: > > [Aug 2 20:27:50] == Using SIP VIDEO CoS mark 6 > [Aug 2 20:27:50] == Using SIP RTP TOS bits 24 > [Aug 2 20:27:50] == Using SIP RTP CoS mark 5 > [Aug 2 20:32:47] == Using SIP VIDEO TOS bits 24 > [Aug 2 20:32:47] == Using SIP VIDEO CoS mark 6 > [Aug 2 20:32:47] == Using SIP RTP TOS bits 24 > [Aug 2 20:32:47] == Using SIP RTP CoS mark 5 > [Aug 2 20:34:26] == Using SIP VIDEO TOS bits 24 > [Aug 2 20:34:26] == Using SIP VIDEO CoS mark 6 > > > I have to turn on sip debugging to find out who's hitting me. However, I > can't just leave it on because it would kill my logging system. > > So, how are other people handling this? Is there an AMI event I want watch > for? I watch for PeerStatus, but since there's no actual peer in the > attack, I don't seem to get an event from AMI. > > Any ideas? > > Mike Diehl. > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: > https://community.asterisk.org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: https://community.asterisk. > org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > Check out the new Asterisk community forum at: https://community.asterisk. > org/ > > New to Asterisk? Start here: > https://wiki.asterisk.org/wiki/display/AST/Getting+Started > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20170819/ea8a2094/attachment.html>