firewall – Giovanni F. Mazzeo De Santolo https://desantolo.com That italian IT guy Sun, 27 Dec 2020 05:38:51 +0000 en-US hourly 1 https://wordpress.org/?v=6.8.3 123042357 OPNsense firewall on Proxmox fix ‘no internet’ https://desantolo.com/2018/11/opnsense-firewall-on-proxmox-fix-no-internet/ Sat, 17 Nov 2018 18:17:25 +0000 https://desantolo.com/?p=566 Continue reading →]]> Quick post to note how I determined and then fixed the internet access issue I was having when I installed OPNsense on Proxmox.

OPNsense virtual machine is configured with VirtiO network drivers.

Other than the obvious “I can’t access anything on the internet” or can’t reach external IP addresses problem I looked at troubleshooting via nmap – because the devices on the network could ping externally (8.8.8.8) and also resolve DNS requests.

In a broken state you may see ‘tcpwrapper’ when testing a known host serving HTTP, like so:

root@test:~# nmap -p 80 -sV 216.58.194.206

Starting Nmap 7.40 ( https://nmap.org ) at 2018-11-17 17:54 UTC

Nmap scan report for sfo03s01-in-f206.1e100.net (216.58.194.206)

Host is up (0.010s latency).

PORT   STATE SERVICE    VERSION

80/tcp open  tcpwrapped

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .

Nmap done: 1 IP address (1 host up) scanned in 7.91 seconds

To fix this issue, ensure that “Disable hardware checksum offload” is  enabled in the OPNsense interface, then reboot the firewall for changes to take effect.

After a reboot, doing another test via nmap will actually respond with HTTP fingerprints, as expected and internet is back.

root@test:~# nmap -p 80 -sV 216.58.194.206

Starting Nmap 7.40 ( https://nmap.org ) at 2018-11-17 18:00 UTC

Nmap scan report for sfo03s01-in-f14.1e100.net (216.58.194.206)

Host is up (0.0096s latency).

PORT   STATE SERVICE VERSION

80/tcp open  http    gws

1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :

SF-Port80-TCP:V=7.40%I=7%D=11/17%Time=5BF0574C%P=x86_64-pc-linux-gnu%r(Get

SF:Request,8A7A,"HTTP/1\.0\x20200\x20OK\r\nDate:\x20Sat,\x2017\x20Nov\x202

SF:018\x2018:00:43\x20GMT\r\nExpires:\x20-1\r\nCache-Control:\x20private,\

SF:x20max-age=0\r\nContent-Type:\x20text/html;\x20charset=ISO-8859-1\r\nP3

SF:P:\x20CP=\"This\x20is\x20not\x20a\x20P3P\x20policy!\x20See\x20g\.co/p3p

SF:help\x20for\x20more\x20info\.\"\r\nServer:\x20gws\r\nX-XSS-Protection:\

SF:x201;\x20mode=block\r\nX-Frame-Options:\x20SAMEORIGIN\r\nSet-Cookie:\x2

SF:01P_JAR=2018-11-17-18;\x20expires=Mon,\x2017-Dec-2018\x2018:00:43\x20GM

SF:T;\x20path=/;\x20domain=\.google\.com\r\nSet-Cookie:\x20NID=146=0dp1WLb

SF:UhFIr1MIVwhAglx_4O6x-0eJHrmYFTov9a3oFxE2-lZSUI_9mmKBFXQZjYbjKbSRiirLZ-U

SF:cfybTiNQR_vmHD2MY4RBHP-hj4K7oyQX4lXuCgrSU7ESRXiX2Jn0qwoLWvvEItnC2hgDHEb

SF:oLJffQrfiEazdGDp5XppPU;\x20expires=Sun,\x2019-May-2019\x2018:00:43\x20G

SF:MT;\x20path=/;\x20domain=\.google\.com;\x20HttpOnly\r\nAccept-Ranges:\x

SF:20none\r\nVary:\x20Accept-Encoding\r\n\r\n<!doctype\x20html><html\x20it

SF:emscope=\"\"\x20itemtype=\"http://schema\.org/WebPage\"\x20lang=\"en\">

SF:<head><meta\x20content=\"Search\x20the\x20world's\x20information,\x20in

SF:cluding\x20webpages,\x20images,\x20videos\x20and\x20more\.\x20Google\x2

SF:0has\x20ma")%r(HTTPOptions,71B,"HTTP/1\.0\x20405\x20Method\x20Not\x20Al

SF:lowed\r\nAllow:\x20GET,\x20HEAD\r\nDate:\x20Sat,\x2017\x20Nov\x202018\x

SF:2018:00:44\x20GMT\r\nContent-Type:\x20text/html;\x20charset=UTF-8\r\nSe

SF:rver:\x20gws\r\nContent-Length:\x201592\r\nX-XSS-Protection:\x201;\x20m

SF:ode=block\r\nX-Frame-Options:\x20SAMEORIGIN\r\n\r\n<!DOCTYPE\x20html>\n

SF:<html\x20lang=en>\n\x20\x20<meta\x20charset=utf-8>\n\x20\x20<meta\x20na

SF:me=viewport\x20content=\"initial-scale=1,\x20minimum-scale=1,\x20width=

SF:device-width\">\n\x20\x20<title>Error\x20405\x20\(Method\x20Not\x20Allo

SF:wed\)!!1</title>\n\x20\x20<style>\n\x20\x20\x20\x20\*{margin:0;padding:

SF:0}html,code{font:15px/22px\x20arial,sans-serif}html{background:#fff;col

SF:or:#222;padding:15px}body{margin:7%\x20auto\x200;max-width:390px;min-he

SF:ight:180px;padding:30px\x200\x2015px}\*\x20>\x20body{background:url\(//

SF:www\.google\.com/images/errors/robot\.png\)\x20100%\x205px\x20no-repeat

SF:;padding-right:205px}p{margin:11px\x200\x2022px;overflow:hidden}ins{col

SF:or:#777;text-decoration:none}a\x20img{border:0}@media\x20screen\x20and\

SF:x20\(max-width:772px\){body{background:none;margin-top:0;max-width:none

SF:;padding");

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .

Nmap done: 1 IP address (1 host up) scanned in 52.89 seconds

root@test:~#

]]> 566 Plex mediaserver on FreeNAS allowing anyone to stream without login https://desantolo.com/2016/12/plex-mediaserver-on-freenas-allowing-anyone-to-stream-without-login/ https://desantolo.com/2016/12/plex-mediaserver-on-freenas-allowing-anyone-to-stream-without-login/#respond Mon, 26 Dec 2016 14:36:52 +0000 https://desantolo.com/?p=449 Continue reading →]]> I’ve been a user of Plex mediaserver for over two years, I set this up on a FreeNAS jail a long time ago and in the past few days I noticed something funny.

Out of nowhere there were two additional streams going on in my server onto the internet, I usually share my library with friends and family but what was curious about this traffic was that Plex was claiming that these two streams were “on my local network”

After reviewing firewall logs and traffic reports (pfSense), I saw traffic from some Australia IP addresses as well as Egypt on my plex port. I discovered that when I setup Plex on FreeNAS I had followed someone’s guide and steps and there was a setting that the guide required on file /usr/pbi/plexmediaserver-amd64/plexdata/Plex Media Server/Preferences.xml

disableRemoteSecurity="1"

Somehow for the past 2 years this has gone undetected, mostly because I have never (until now) detected anyone that I did not trust streaming my media library. Some Google searches told part of the story, some websites and facebook pages started sharing links to my public IP address and plex port.

I setup a quick SSH tunnel to one of my servers to get an ‘external’ view from outside my network and sure enough, you could see my library and stream anything, no login required!

After some research, even though my plex settings were set to require a login to be able to stream settings set on the Plex server settings page were being ignored. Finally when I checked the XML file manually I found out that the security was being disabled and so that is why Plex was not applying the settings.

If you have noticed any weird traffic or use the setting above on your FreeNAS + Plex jail – please be wary and you may want to close that loophole by removing that string from the XML Preferences file and restart Plex. You can whitelist your local network so that no login is required (I have 172.16.0.0/20 whitelisted).

It remains a mystery how these people found my public IP address, but I assume someone port scanned me for vulnerabilities and found the web portal wide open, so they started sharing the link.

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