Ubuntu Security :: Allow SSH Tunnel Through Ufw Firewall?
Jun 15, 2011
I have set up a Ubuntu 10.10 server. I have been using ssh tunnels to encrypt my web traffic at public wifi. I am trying to make this server as secure as posible so I enabled ufw. I allowed SSH and HTTP traffic in and denied everything else. But when I do that I can not use SSH -D because when I try to visit a webpage it does not load and I get the following.
Code:
uname@mybox:~$ channel 3: open failed: connect failed: Connection timed out
^C
uname@mybox:~$ fclchannel 4: open failed: connect failed: Connection timed out
^C
uname@mybox:~$ exit
logout
What do I have to do to allow ufw to allow ssh tunnels through?
I have an security cam with a built-in webpage inside my home network. That camera is using basic HTTP authentication instead of SSL. I want to be able to access the camera's webpage from outside my network, but I don't want to open an unencrypted video stream to the outside world. Right now, I'm doing some cumbersome ssh tunneling where I bounce off an ssh server like: ssh -N -L 9090:[URl]..and then I connect to my web page like: http://localhost:9090
But this is a pain. Now, gentle reader, I beseech you to tell me how I can use linux (Ubuntu) to get a fully encrypted SSL connection to my internal web page without the hassle of creating an ssh tunnel each time. I believe I can use stunnel, but I'm not sure of the command.
I've set up a Lan-to-Lan (routed) OpenVPN tunnel. For redundancy I want to set up a second VPN tunnel on a fallback gateway/firewall on the client side. Currently, both sides (server/client) know how to route packets across each others physical LAN. So no NAT is used. When the primary gateway (fw1) is connected to the VPN server all traffic runs via the fw1 tunnel. Than when the secondary gateway (fw2) connects to the VPN server and fw1 is still connected all traffic for fw1 will be delivered to fw2 and effectively destroying traffic intended for fw1. This is of course no problem if I first shutdown (fence) fw1, than set up fw2 to use the gateway IP address from fw1 and set up the VPN tunnel to the VPN server. Effectively replacing fw1 with fw2 on the client side. However, I can't seem to find a decent howto.
I am also exploring the possibility to let both tunnels active and let OpenVPN (or another tool) decide how to route packets back and forth the different LANs. A virtual IP between two gateway's both running a VPN or something similar. This would be the preferred method of course. However, I don't know how to tackle this one but I'm pretty sure there are people out there who are happy to share their 2 cents.
I want to setup firewall protection with iptables to support IPSec tunnels. That is, the firewall will drop anything from any host if it is not from an established IPSec tunnel. And it will accept anything (any protocols) if it's from an IPSec tunnel.
That is, I need also to open up ping to make ping work. But if I open up icmp, I cannot prevent pings from hosts that's outside my IPSec tunnels. This defeats my purpose.So if my purpose is to allow "anything" within the tunnel and disallow/drop anything outside the IPSec tunnels, how should I setup the iptables rules?
I have an SSH tunnel setup between a local server and a remote postfix relay VPS. This is so we can route all our outgoing mail through this SSH tunnel to a private relay VPS, this seems to give us much more consistent mail delivery than using our ISP's relay. So the SSH tunnel is set to route port 1025 on machine A to port 25 on the VPS This part of it is working perfectly and has been for months. However today I wanted to set our e-mail newsletter software (on the same network as the SSH tunnel start-point) to send through the SSH tunnel. So I punched in the IP/port... 192.168.1.5:1025 but it doesn't work. Is there something I need to do to allow connections from other machines on the LAN to access the start-point of the SSH tunnel? Or are SSH tunnels restricted to localhost connections only?
Now I know that the first is the tunnel end but how can I connect the two lines if I don't know the port number (ie: someone else estabilieshes another tunnel)
I have squid as a proxy on the Suse box, and with the default firewall I have to enable masquerading to allow clients on the eth3:1-3 to send and receive mail through the Suse box. I found the Suse firewall completely inadequate (all P2P software/connections are allowed once you enable masquerading) and had to install ConfigServer Security & Firewall. In die configuration of csf I could get my way around getting smtp to work for the eth3:1-3 clients, but pop3 connections does not go through the box. I know I need to allow port 110 and 995 to masquerade of NAT (or something) and then the same for port 22
I have Ubuntu running on an old PE server. It is running Virtualbox with an instance of Ubuntu inside. The instance is there to run my honeypot.
The server box IP is192.168.1.10. The Virtualbox is bridged with it's own IP of 192.168.1.200. The honeypot daemon is listening to 192.168.1.201 with arpd.
I set up the UFW with DENY. And then enabled only the ports leading to the honeypot scripts which are abound to IP .201. I then forwarded the ports necessary to run VNC to .200.
Here is the UFW status: buntu@ubuntu-desktop:/var/lib$ sudo ufw status Status: active To Action From -- ------ ---- 192.168.1.201 21/tcp ALLOW 21/tcp 192.168.1.201 4444/tcp ALLOW 4444/tcp 192.168.1.201 5544/tcp ALLOW 5544/tcp
I have a VPS (Ubuntu 8.04 server eition) and as such am stuck with using a software firewall.
i currently have UFW installed.
I would ideally like to have my firewall be a little rude, or rather just not polite. I know what i am asking will break the RFC, but i consider this ok due to the security benefits.
I would like to have my firewall 1) ignore (eg drop without responding)all packets that dont start with a syn flag 2)for all other traffic that is currently blocked, have it dropped (again drop it without responding)
If there are any other rules you can think of i would like to know them. I already have only the services i want open and the rest blocked.
I've been using Windows for quite a few years now. I loved the way how I used to set incoming/outgoing rules for my applications. But I'm having hard time doing that in Ubuntu. I tried searching for a good GUI for iptables but I need your help selecting the best. I might learn iptables someday but for the time being I will be using a nice GUI. I'm currently using GUFW, I've tried Firestarter. All I need is a firewall that would allow me to configure rules for my applications.
I am a Linux newbie so please bear with me if I sound stupid. I was checking out how to set up a firewall for my system and landed on this webpage: [URL]. But I am so confused with how this ufw application works. What I understand is that once I set it to "default deny" it prevents unauthorized incoming connection but what does it mean when the author says to add exceptions for services I need? When do I need to do that? Also what's an SSH server?
I'm using Postgresql 8.4.2-2. I'm trying to remote into my server securely. I figure I could do so with ssh. Apparently I figured correctly, as per, [URL] and [URL] I setup the ssh tunnel. ssh -L 5432:serverip:5432 Then I setup pgadmin3 to connect as follows:
An error has occurred: Quote: An error has occurred: Error connecting to the server: server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request.
I'm not sure what the problem is. I can connect with Code: psql from the cli after connecting to the terminal via ssh. So I know that I'm using the correct password.
I need to have a group of computers that connect to a remote site and run lynx to view some php pages that interface with mysql (that's a mouthful)For version control, I would like to keep only one central copy of the web files.
Personal data is sent, so rather than setup https server or SSL mysql encryption, I decided to create a "tunnel" to a Terminal Server using SSH.
I flirted with the idea of setting up VPN tunnels between the clients and a DMZ network but I don't want to add a bunch of complexity.
I just wanted to make sure that I wasn't creating a gaping security hole.
I'm involved in a project to students set up a network security training lab using vmware. I want to simulate (in a very rough way) scanning through a poorly configured router or firewall. The easiest way I can think of to simulate this is to use a linux vmware image with two virtual nic cards to act as a firewall with the attacker on the outside network and a domain controller, web server, and database server on the inside network.
I would like to start students off with a firewall script that exposes everything on their internal network to the attacker. Is there an easy way to (mis)configure iptables to do this?. The model I'm trying to replicate is something like this. Attackers were on a 10.10.x.x network, defenders were on a 192.168.x.x network. As an attacker I could nmap 192.168.x.x and see every machine and every service on the defenders side even if they moved a service to an unexpected location. how I can implement a similar configuration using a linux image as firewalls/routers in vmware?
I have a set of iptables rules generated by Firestarter, and i'm in the process of trying to familiarise myself with iptables itself, but there's one particular rule which is confusing me, perhaps somebody could explain it to me
I'm running the firestarter firewall and its been showing the odd ssh attempt quite often. e.g. I've had 4 attempts today, 3 in the last 40mins. I realize that this may be nothing to serious but it's got me curious, aside from having a secure password (which I have) is there anything that else that I can do to ensure that my system is as secure as possible from ssh? I do use ssh within my home network so I don't want to disable it completely.
I have noticed interesting problem. I use two browsers - Firefox and Konqueror. Konqueror is configured to use tor, Firefox not. Using Gufw I block all incoming and outgoing traffic and it works while using Firefox, I mean that I can't view any www site and it is ok. But if I use Konqueror I can establish any conection. How to understand this? Should I have different firewall while using tor?
I know that GNU/Linux does not need a firewall (due to iptables), but I would like a basic firewall that would watch incoming and outgoing connections. I would prefer it to have a try icon and be able to run as a regular user, such that I can add it to my .fluxbox/startup file. Anyone know of any good ones? They don't actually have to interface into iptables (because I would do that myself), but if they do it would be a bonus.
I run a small (cabled) network between a desktop with XP with two printers hooked to it and a laptop with Ubuntu 10.04.1 64b. I can approach and use these printers from my laptop and filesharing works also. BUT ... this only works when my Ubuntu firewall (Gufw 10.04.5) is switched off. I am operating behind my router_modem which has a hardware type of firewall switched on at all times so I presume I'm safe. Now my questions:
1. Is this really safe enough? 2. What kind of settings would Gufw need to be able to use it AND use my mini-network for printing? I have no experience whatsoever with firewall rules and settings.
I am currently trying to make my computer as secure as it can possibly be. I am configuring the firewall to be restrictive by default, but I have some programs that are still unable to connect to the internet.
1. Pidgin Internet Messenger (I use AIM and MSN) 2. Skype
