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    Scheduled Pinned Locked Moved General pfSense Questions
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    • D
      doktornotor Banned
      last edited by

      @Trel:

      if you have Snort/Suricata installed

      Noooooooooooooo!!!

      1 Reply Last reply Reply Quote 0
      • K
        kejianshi
        last edited by

        !!!

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        • H
          heper
          last edited by

          (unbound has been enabled for more then a month without issues … until an hour ago)
          i've suddenly been experiencing the blank pages + dns redirects to buydomains.com for lots of valid domains.

          i tried to fix it by enabling dnssec ... didn't help

          for now i've enabled "forwarding mode" on unbound ... this seems to fix the issue.

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          • DerelictD
            Derelict LAYER 8 Netgate
            last edited by

            Unbound in resolver mode?  That makes no sense.  The deal is is that makes it pretty much impossible to affect everything.  They have to target specific name servers for specific domains (or .com, or . (root) etc..

            What DNS servers are you handing out to your clients?  Running unbound means nothing if your clients are going to 8.8.8.8 / 8.8.4.4 for DNS.

            Want an easy way to find out?  Block TCP/UDP 53 on LAN to everything but your unbound and see what breaks.  :)  Or pass with logging and see what's logged….

            Chattanooga, Tennessee, USA
            A comprehensive network diagram is worth 10,000 words and 15 conference calls.
            DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
            Do Not Chat For Help! NO_WAN_EGRESS(TM)

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            • K
              kejianshi
              last edited by

              After you properly set up DNS and DNSSEC, you still have to clear DNS cache on each client and also have to make sure your clients are not infected with something or running some stupid browser add-on that hijacks things.

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              • 2
                2chemlud Banned
                last edited by

                @Derelict:

                ….  Block TCP/UDP 53 on LAN to everything but your unbound and see what breaks.  :)  Or pass with logging and see what's logged....

                Port 53 is not allowed at my network for more than a year. Doing fine with the DNS servers in the General setup and keep awful devices such as Buffallo Linkstations etc from phoning home…

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                • S
                  swix
                  last edited by

                  When it happened, all dns requests returns "195.22.26.248" as IP address (also for invalid domains):

                  swix@pc:~> host google.ch
google.ch has address 195.22.26.248                                                                                                                                                                   
google.ch mail is handled by 10 mx1.csof.net.                                                                                                                                                         
google.ch mail is handled by 10 mx2.csof.net.                          

swix@pc:~> host aaaaaafadkfjdu93jifa.ch
aaaaaafadkfjdu93jifa.ch has address 195.22.26.248                                                                                                                                                  
aaaaaafadkfjdu93jifa.ch mail is handled by 10 mx1.csof.net.                                                                                                                                        
aaaaaafadkfjdu93jifa.ch mail is handled by 10 mx2.csof.net.

                  Unbound server is set as local resolver for a small LAN, with no forwarding to remote resolvers, so everything should be resolved locally.

                  Still investigating about how this could happen, and I will update this thread as soon as I find anything.
                  Kind regards.

                  PS: it apparently happened to last week, and I then disabled DNSSEC Support, but as it happened again it doesn't seem to be related.

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                  • P
                    Pakken
                    last edited by

                    So far happened only one time for me.
                    After enabling dnssec and disabling all the forwards to public dns servers it seems to be fixed.
                    In addition, I've created a floating rule to block every local subnet to that 195.22.0.0 range.

                    Will keep you updated.
                    To be honest the strange thing is that in a couple of years of pfsense pre-2.2 and dnsmasq this never happened.
                    The problem appeared straight after upgrading to 2.2 and dnsresolver even tho, once again, only happened one time so far to me.

                    Best regards

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                    • D
                      doktornotor Banned
                      last edited by

                      @swix:

                      When it happened, all dns requests returns "195.22.26.248" as IP address (also for invalid domains):

                      I'd certainly investigate the LAN for possible infection. Just look at the amount of malicious crap associated with that IP:
                      https://www.virustotal.com/en/ip-address/195.22.26.248/information/

                      If you have some ISP-supplied router/modem in front of the pfSense box, Google for possible well-known firmware exploits as well.

                      @swix:

                      PS: it apparently happened to last week, and I then disabled DNSSEC Support, but as it happened again it doesn't seem to be related.

                      Disabling DNSSEC most certainly does NOT help anything. Very broken idea.

                      1 Reply Last reply Reply Quote 0
                      • S
                        swix
                        last edited by

                        @doktornotor:

                        I'd certainly investigate the LAN for possible infection. Just look at the amount of malicious crap associated with that IP:
                        https://www.virustotal.com/en/ip-address/195.22.26.248/information/
                        If you have some ISP-supplied router/modem in front of the pfSense box, Google for possible well-known firmware exploits as well.
                        ng DNSSEC most certainly does NOT help anything. Very broken idea.

                        Thanks for the suggestion, yes, I will try to have a look on this, but the network device (VDSL Bridge Zyxel P-870M) is in bridge mode, so I have no way to connect directly to it (or only via a serial console, with a cable to be found yet).  Newest Firmware = 2009.

                        It just happened again a few minutes ago (3rd time today).

                        I was also trying to see if the root-servers file was tempered anyhow, but /etc/unbound/root.hints does not exist at all on the pfsense router.

                        Log extract when problem is happening, with many requests to "ns*.csof.net" servers where it shouldn't be the case  :

                        
Feb  9 12:55:25 pf unbound: [39509:0] info: reply from <4.85.in-addr.arpa.> 195.186.196.180#53
Feb  9 12:55:25 pf unbound: [39509:0] info: query response was ANSWER
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving daisy.ubuntu.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns1.canonical.com. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns2.canonical.com. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns3.canonical.com. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns2.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns3.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns1.csof.net. AAAA IN       
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns2.csof.net. AAAA IN  
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns3.csof.net. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns4.csof.net. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns1.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns3.csof.net. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: resolving ns1.csof.net. AAAA IN
Feb  9 12:55:28 pf unbound: [39509:0] info: response for ns3.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: reply from <com.>54.77.72.254#53
Feb  9 12:55:28 pf unbound: [39509:0] info: query response was ANSWER
Feb  9 12:55:28 pf unbound: [39509:0] info: response for ns2.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: reply from <com.>54.77.72.254#53
Feb  9 12:55:28 pf unbound: [39509:0] info: query response was ANSWER
Feb  9 12:55:28 pf unbound: [39509:0] info: response for ns1.canonical.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: reply from <com.>54.77.72.254#53
Feb  9 12:55:28 pf unbound: [39509:0] info: query response was ANSWER
Feb  9 12:55:28 pf unbound: [39509:0] info: response for daisy.ubuntu.com. A IN
Feb  9 12:55:28 pf unbound: [39509:0] info: reply from <ubuntu.com.>195.22.26.248#53          ########## wrong ! 
Feb  9 12:55:28 pf unbound: [39509:0] info: query response was ANSWER</ubuntu.com.></com.></com.></com.>

                        TBC.

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                        • T
                          Trel
                          last edited by

                          I just want to clear up a few things

                          When any DNS Server can be used (not just unbound) and DNS Sec is set to off
                          -A DNS lookup from any computer to one of the domains cause EVERY subsequent lookup to resolve to "195.22.26.248"
                          (persists until unbound service is restarted)

                          When only unbound can be used and DNS Sec is set to ON, and port 53 is blocked except to pfsense
                          -A DNS lookup from any computer to one of the domains causes unbound to stop resolving anything, all lookups fail
                          (persists until unbound service is restarted)

                          Thanks to a packet capture I was able to find which domains were being looked up, I then overrode the hosts and set the IP to 0.0.0.0 so they resolve but obviously can't get out

                          When only unbound can be used and DNS Sec is set to ON, port 53 is blocked except to pfsense, AND the hosts are overrode so Unbound doesn't make any query on those domains outward either
                          -All problems seem to cease

                          (Also, due to the packet capture, I can say the original request is coming from an unrooted Android device requesting port 80 on a few of those sites, based on the URL, it's requesting an API for determining the outward IP)

                          EDIT: here's the overrides I did to flat out prevent those names from being resolved.

                          overrides.jpg
                          overrides.jpg_thumb

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                          • S
                            swix
                            last edited by

                            Thanks for your update Trel, we're still searching here, but enabling DNSSEC does not stop the issue.    And last time, it stopped by itself after about 5 minutes.

                            When "broken", all webrequests are redirected to http://xsso.www.example.org (with the original domain name instead of example.org).

                            GET /domain/www.example.org HTTP/1.1
Host: sso.mlwr.io
User-Agent: Mozilla/5.0 (X11; Linux x86_64) (...)
Accept-Encoding: gzip, deflate, sdch
Accept-Language: de,en-US;q=0.8,en;q=0.6
Cookie: anbsso=a5f4221ae2729d945150c83748e2ea12 (...)

Response: HTTP/1.1 302 Moved Temporarily
Server: nginx-perl/1.2.9.7
Date: Mon, 09 Feb 2015 14:29:31 GMT
Content-Type: text/html
Transfer-Encoding: chunked Connection: keep-alive
Set-Cookie: btst=b1b2035cffe818d92d7f6604a1318beb|myip|...
Location: http://xsso.www.example.org/a5f4221ae2729d945150c83748e2ea12

                            Just increased the logfiles size to try to see more next time it happens and added monitoring to get an alert directly.

                            And another view with wget, with and without https, with the same "lolcat" I already saw in another thread:

                            
om@ompc:~> wget http://www.example.org
--2015-02-09 13:55:37--  http://www.example.org                                                                                                                                                     
Resolving www.example.org (www.example.org)... 195.22.26.248                                                                                                                                           
Connecting to www.example.org (www.example.org)|195.22.26.248|:80... connected.                                                                                                                        
HTTP request sent, awaiting response... 302 Moved Temporarily                                                                                                                                      
Location: http://sso.mlwr.io/domain/www.example.org [following]                                                                                                                                      
--2015-02-09 13:55:39--  http://sso.mlwr.io/domain/www.example.org
Resolving sso.mlwr.io (sso.mlwr.io)... 195.22.26.248
Reusing existing connection to www.example.org:80.
HTTP request sent, awaiting response... 200 OK
Cookie coming from sso.mlwr.io attempted to set domain to example.org
Length: unspecified [text/html]
Saving to: ‘index.html.3’

om@ompc:~> wget https://www.example.org
--2015-02-09 13:55:43--  https://www.example.org/
Resolving www.example.org (www.example.org)... 195.22.26.248
Connecting to www.example.org (www.example.org)|195.22.26.248|:443... connected.
ERROR: cannot verify www.example.org's certificate, issued by ‘/CN=lolcat’:
  Self-signed certificate encountered.
    ERROR: certificate common name ‘lolcat’ doesn't match requested host name ‘www.example.org’.
To connect to www.example.org insecurely, use `--no-check-certificate'.
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                            • T
                              Trel
                              last edited by

                              You said you enabled DNSSEC, but question, what do you have in

                              System -> General -> DNS servers?

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                              • S
                                swix
                                last edited by

                                PS:  installed packages on this router: arpwatch, bandwithd, cron, darkstat, mailreport, nrpe, rrd summary, openvpn client export.

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                                • S
                                  swix
                                  last edited by

                                  @Trel:

                                  You said you enabled DNSSEC, but question, what do you have in
                                  System -> General -> DNS servers?

                                  Completely empty, so shoud unbound start with root servers directly.  I was wondering where was the hints file for unbound, but it seems to be directly in the binary file (strings unbound) :

                                  A.ROOT-SERVERS.NET.
198.41.0.4
B.ROOT-SERVERS.NET.
192.228.79.201
C.ROOT-SERVERS.NET.
192.33.4.12
D.ROOT-SERVERS.NET.
199.7.91.13
E.ROOT-SERVERS.NET.
192.203.230.10
F.ROOT-SERVERS.NET.
192.5.5.241
G.ROOT-SERVERS.NET.
192.112.36.4
H.ROOT-SERVERS.NET.
128.63.2.53
I.ROOT-SERVERS.NET.
192.36.148.17
J.ROOT-SERVERS.NET.
192.58.128.30
K.ROOT-SERVERS.NET.
193.0.14.129
L.ROOT-SERVERS.NET.
199.7.83.42
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                                  • DerelictD
                                    Derelict LAYER 8 Netgate
                                    last edited by

                                    Ok.  So what are the DNS servers configured on the client?

                                    Chattanooga, Tennessee, USA
                                    A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                    DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                    Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                                    • S
                                      swix
                                      last edited by

                                      @Derelict:

                                      Ok.  So what are the DNS servers configured on the client?

                                      Set via DHCP, simply the router's ip address:

                                      
   option domain-name-servers 192.168.1.100;
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                                      • DerelictD
                                        Derelict LAYER 8 Netgate
                                        last edited by

                                        And you've actually verified that's the case on the client?

                                        Chattanooga, Tennessee, USA
                                        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                        Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                                        • D
                                          doktornotor Banned
                                          last edited by

                                          @swix:

                                          Thanks for your update Trel, we're still searching here, but enabling DNSSEC does not stop the issue.

                                          It does NOT stop the issue on domains that are not signed, no. Also, it will NOT prevent the DNS hijack if your clients are NOT using pfSense or another DNSSEC-enabled resolver, even if the zones are signed. It will prevent resolving domains to malicious crap for the rest.

                                          • Block/redirect all DNS queries on LAN to pfSense
                                          • Find and reimage infected crap.
                                          1 Reply Last reply Reply Quote 0
                                          • T
                                            Trel
                                            last edited by

                                            @doktornotor:

                                            • Find and reimage infected crap.

                                            I agree, but I would like to point out the way it affects pfsense/unbound is not a good thing at all.

                                            A lookup on a completely isolated network segment made unbound start giving bad resolutions to ALL network segments when other DNS servers were permitted, and when they were blocked, unbound simply stopped replying.

                                            That's not really the best outcome for a single computer looking up a bad domain.

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