Questions tagged [tunneling]

tunneling refers to a mechanism in which one network protocol encapsulates a different payload protocol.

25
votes
2answers
49k views

How can I tunnel through an SSH server for application layer protocols such as HTTP/s and FTP?

Are there client programs that allow me to "tunnel" through my SSH enabled server for normal Internet requests such as HTTP(s)? If so what are they and can someone point me in the right direction? ...
23
votes
2answers
4k views

Is telnet secure through SSH tunneling

Firstly sorry, maybe dumb question, but I have one service running on my server which can be operated only by telnet (port 23), but I know that telnet is insecure, so I blocked port 23 in iptables ...
22
votes
2answers
16k views

Security Concerns with X11 Forwarding

What are some of the security concerns and reasons either for or against allowing X11 Forwarding. I have generally taken an approach of not allowing it under the blanket guise of security. Recently, ...
21
votes
5answers
14k views

Do you detect/react to DNS tunnelling?

I've just seen a talk about tunnelling TCP/IP over DNS requests, because port 53 UDP is usually open and unfiltered. What techniques exist to detect and block such tunnels, and have you ever seen that ...
18
votes
4answers
8k views

How to use public WiFi safely?

The Dangers of Open Wi-Fi How does one go about sending valuable information (for example inputting email username and password) over a free password-less public WiFi network? The only option that I ...
17
votes
6answers
10k views

How does a network admin block the reverse SSH in company?

Given firewall inbound: all are blocked outbound: allow port 80, 443 Problem colleagues are still able to ssh to home device by port 80/443, and establish a reverse ssh tunnel from company to home, ...
15
votes
2answers
12k views

How safe is Tor from MITM/snooping attacks?

I am behind an HTTP proxy, and I frequently tunnel out via an ssh -D SOCKS proxy (I have access to a couple of outside servers which I can tunnel to) when the HTTP proxy causes problems1. Now, this ...
12
votes
1answer
1k views

Does a VPN provide any security benefits over sshuttle or a vanilla ssh tunnel?

I use sshuttle to tunnel my traffic through one of my remote boxes whenever I'm in a cafe or connected to an insecure network. Does a VPN provide any additional security benefit over this kind of ...
9
votes
4answers
7k views

Computer sending unstopped ICMP echo request to an IP

I noticed while hanging in Microsoft Network Monitor that my computer is sending ICMP echo request to an arbitrary IP address 202.39.253.11. I looked for the owner of this IP and I found it is owned ...
9
votes
1answer
658 views

Maximum number of nodes with IPSec?

From my understanding, for incoming packets over IPSec, the Security Association (SA) is identified by the SPI field of the ESP header. Then let's say I have a bunch of nodes where each node wants to ...
8
votes
4answers
1k views

How to tunnel all network communication?

I'm looking for a way to tunnel all network communication from my laptop through another computer. I can control the software on both the laptop and the computer. The connection between them should be ...
8
votes
2answers
4k views

What are the security implications of SSH tunneling?

We have an internal lan (not connected to internet, all internal ip addresses, behind a firewall, no routing to outside), we also have a machine that sits on the edge of our lan (two nics, one on the ...
8
votes
5answers
3k views

Creating tunnel with most ports closed?

How can I create a proxy tunnel from a network that has all ports but port 80 closed? I guess I'd have to bind SSH on my server to port 80, but would that introduce problems to my home network since ...
8
votes
3answers
3k views

What is the difference between encrypted data and data sent through an encrypted tunnel?

I am looking at different VPN protocols. L2TP does not provide encryption so require IPSec to encrypt the data IPSec tunnel provide encryption to the tunnel What is the difference in terms of the ...
8
votes
1answer
24k views

How can I tell if a PPTP tunnel is secure?

PPTP has been demonstrated to be broken in many ways, and most installations are insecure. But it is also theoretically not broken if configured correctly. As an end-user, is there a simple way for ...
8
votes
4answers
968 views

Should I tunnel multiple TCP connections through a TLS/SSL tunnel or use TLS/SSL for each connection?

I am developing an application that runs on Windows PCs. The application is able to connect to some kind of devices within a LAN. It can create multiple TCP-connections to the device it is connected ...
7
votes
1answer
2k views

How to deal with tunnel applications such as TeamViewer on the corporate network

Our IT department uses TeamViewer to provide support to users at remote locations. More recently we've noticed that users are using TeamViewer to get support for their lab equipment from vendors. ...
6
votes
3answers
2k views

Why is tunneling so important in pen testing?

I am curious why tunneling is so important in pen testing. If one has control of one machine in a network, then using that machine, one can run nmap and web apps and try to find out vulnerabilities.. ...
6
votes
1answer
842 views

DNS Tunneling - Mitigation

I believe the root cause for DNS tunneling is because the internal hosts are allowed to do recursive queries of external domains. For DNS tunneling to work, an internal host should be able to send ...
5
votes
3answers
26k views

How to create ssh tunnel using netcat?

I want to create reverse connection between two machines, but these is a firewall in the middle preventing all connections, except ssh. I want to create ssh tunnel using netcat, could you please tell ...
5
votes
3answers
33k views

How to force ALL programs to use my Proxy?

I have a local proxy on my PC. (localhost:8888) But unfortunately there are many programs which are not able to go through this proxy. So how can I force all my programs to go through my local proxy (...
5
votes
3answers
915 views

Should traffic between two hosts in the same data center be encrypted?

We have two hosts, theoretically in the same data center. The two machines are hosted at Online.net. We're having a bit of a debate: should the traffic between the two hosts be encrypted. The traffic ...
5
votes
2answers
269 views

If two endpoints establish a mutual authenticated connection (TLSv1.0) is the medium between the endpoints a concern?

What are the vulnerable areas when two endpoint connect via TLS? Does the physical layer or data link layer a factor of security concern between the two endpoints? Does it matter in terms of security, ...
5
votes
1answer
1k views

How should I tunnel arbitrary protocol traffic over HTTPS?

I'm posting this question from a moving train! (Ok, maybe that's not so impressive.) This train has an annoying WiFi - it's low-throughput, high-latency, tends to lose packets, and blocks most kinds ...
4
votes
2answers
561 views

Can a Government block a specific app traffic, even with a VPN running?

A few minutes ago, there was a terror attack on a nightclub in Istanbul/Turkey(Thoughts and prayers to the victims and families), usually, the Government limits most of the communications apps traffic ...
4
votes
1answer
1k views

ISP and ssh tunneling

I have a question about ssh tunneling. Is it possible for the ISP to realize the destination server which I want to connect it via ssh tunneling? I mean the destination website which I want to visit ...
4
votes
1answer
1k views

Is it sensible to tunnel TLS traffic over another TLS?

I'd like to secure my application's traffic using TLS with pre-distributed self-signed certificates (as a drop-in replacement of plain TCP). In some cases, two clients won't be able to talk to each ...
4
votes
1answer
2k views

L2TP/IPSec: Mutual authentication BEFORE user can access VPN

I came across a question You are the network administrator for your company. You have deployed Windows Server 2008 on all server computers in your company. You have deployed the Network ...
4
votes
1answer
537 views

Trying to tunnel a reverse shell out of an internal network

I am practicing performing a pentest and getting stuck trying to get an interactive reverse shell from an internal machine to my attacker machine. This is what I have done so far: Me(attacker): 67....
3
votes
3answers
167 views

Can the root of a system access to unencrypted data when using a double tunnel?

I connect to a DMZ gateway system (B) which is not secured. From this machine (B) I can connect to the final destination (C). A-->B-->C I created a ssh tunnel from A to B and forwarding the port 22 ...
3
votes
3answers
4k views

Using /usr/bin/passwd as login shell

I have a requirement to set up a SSH tunnel between two hosts. SSH server runs on a Linux host, and the SSH client (PuTTY) runs on a Windows host. I have set up a separate user account (say 'tunnel') ...
3
votes
4answers
6k views

Connections through Firewalls explained

I'm looking for a good explanation of how connections work through firewalls. I've got the idea of packaging(encapsulating) some protocol inside another one as its payload when tunneling. But what I ...
3
votes
2answers
89 views

Security concerns with external MySQL access using tunnelling

I have gotten my personal vServer with a standard installation of Ubuntu Server 16.04 and I wanted to install and configure a MySQL server on it. I was considering to disable direct external access, ...
3
votes
4answers
3k views

How to know if accessing to a VPN service is safe and won't steal my data

I want to know if a VPN service is safe or not. If the VPN server itself can catch or sneak peek my data? Or as long as it is a VPN service, then the security is protected by the algorithm itself? ...
3
votes
1answer
5k views

How can I detect if someone is using an ssh tunnel as a proxy to connect to a VPN?

I've got an SSH server setup in a remote location, which I use to tunnel traffic from an android tablet. On the tablet, I have the Cisco AnyConnect app to connect to my company's VPN. We want to be ...
3
votes
1answer
563 views

Pivoting with Metasploit

I am trying to exploit a Windows VM on a different subnet behind a dual home Linux VM where I already have a shell. To keep it simple, I have a meterpreter reverse_tcp shell on the Linux VM (192.168....
3
votes
0answers
565 views

Does enabling VPN on our router increase the risk of our network being exposed to the outside network? [closed]

We are thinking about using VPN to connect our remote office and the main office and also support developers working from home. To do this, we are planning to purchase 2 CISCO (or similar) routers to ...
2
votes
3answers
136 views

Secure tunnel set up in an office environment

Suppose I am a rogue employee and I want to syphon some sensitive data out of the office and I only have office internet access for this. My office internet access needs to go through a proxy server, ...
2
votes
1answer
2k views

X windows security: VNC and X server vs xpra

I have a CentOS server that currently has no X server on it. It will be used for doing statistical crunching and providing other services (probably via a web interface). The main security for the ...
2
votes
1answer
589 views

Captive portal DNS tunneling

I recently had a meeting with a security researcher who told me about tunnelling over a captive portal using DNS. I have done some research into this but I was wondering what is the simplest way to ...
2
votes
1answer
95 views

Is the same key used for Authorization and Encryption? (SSH Tunnel)

I am a bit confused on how SSH encryption works. From reading this question, I see you can use a private key to authenticate with the -i flag. I also know think that SSH encrypts data using ...
2
votes
1answer
580 views

Does AH in tunneling mode provide encryption?

I've been reading on IP sec for a few days, and i have some confusion on the differences between AH and ESP in tunnel/transport mode. I understand that AH only provides authentication and integrity ...
2
votes
2answers
4k views

Squid proxy and VPN software

I have some questions about squid proxies, we set a squid proxy server to block certain web sites for users. and some users only can access one website that related to our work.but after install some ...
2
votes
1answer
1k views

Does a Server connecting to port 3544 pose an increased risk

I had look at the firewall logs and i can see my production server connects to microsoft (13.92.90.48) on UDP port 3544. A quick reading suggests this is to do with Teredo tunneling (IPV6 translation ...
2
votes
2answers
470 views

Authentication helpers for tunneling through an HTTP proxy?

corkscrew is quite good for tunning SSH through an HTTP proxy. However, it only supports basic authentication. Have other people developed similar software supporting other types of authentications? ...
2
votes
1answer
154 views

Tunneling over a HTTP subfolder?

I have a firewall, which only forwards HTTP requests, and only if the request is pointing to something in a /admin/ folder, so it only lets through requests like this: http://www.anysite.com/admin/...
2
votes
1answer
56 views

What's the difference between SSH tunneling and login into the same SSH server and executing commands?

Consider these 2 scenarios. (1) Let's say I login into an SSH server named A normally using ssh [username] @ [IP address of A]. And now I connected to another server named B which is accepting ...
2
votes
1answer
905 views

Tunnel ssh over http with custom headers

I'm trying to set up corkscrew to make an SSH tunnel over HTTP, but I need to add custom headers after the "CONNECT" statement and before the ssh tunnel. Does corkscrew support it? If yes, how can I ...
2
votes
1answer
369 views

How to obfuscate SSH tunnel Mac?

I am looking to test a DPI (deep packet inspector). I currently have it set up to block SSH connections (which it does successfully). I have learned that DPI can be bypassed by obfuscating/encrypting ...
2
votes
1answer
2k views

Using RSA for Web Application Authentication

I have a network that is only accessible through bastion servers over ssh. In it, I am developing web applications that are exposed to end users via GUI's served up over websockets. All traffic into ...