42
votes
Is telnet secure through SSH tunneling
Yes. Controlling a Telnet client through an SSH tunnel is, in practice, as safe from eavesdropping as using any other program (e.g. a Bash shell) through the tunnel.
Telnet is called an insecure ...
- 44.6k
27
votes
How does a network admin block the reverse SSH in company?
SSH traffic looks different from HTTP and HTTPS. SSH traffic simply tunneled through port 80 or 443 (i.e. ssh -p80...) can be detected by looking at the first response packet already which contains ...
- 198k
24
votes
Accepted
Is telnet secure through SSH tunneling
The traffic cannot be sniffed. It is not ideal - you're adding extra steps to arrive at a secure connection, so performance will suffer - but it is safe from sniffing at least at the network level. ...
- 2,054
9
votes
Accepted
Does a VPN provide any security benefits over sshuttle or a vanilla ssh tunnel?
No. It is just different VPN protocol. If NSA can't decrypt SSH, you are fine with sshuttle, if you use strong VPN there should be nothing different.
If you set up weak primes for diffie-hellman key ...
- 5,609
9
votes
Accepted
SSH reverse tunnels: can the intermediate server eavesdrop on an SSH session?
Assuming that there is no active MITM attack going on (which can be detected by properly checking the host keys when connecting to rpi), the server sees only the SSH traffic between laptop and rpi.
...
- 198k
6
votes
How does a network admin block the reverse SSH in company?
A way to make it a bit harder could be to have an HTTP proxy in place so that connections can't be made directly over 80/443 anymore unless it's a valid HTTP connection, but even that can be bypassed ...
- 79
6
votes
Accepted
WireGuard / CVE-2019-14899: How secure the protocol really is?
Is this information technically correct?
Yes, but please note that there is a modification of the previous attack which cannot be stopped by the previously recommended mitigations - see Blind In/On-...
- 198k
4
votes
How does a network admin block the reverse SSH in company?
Here, they have blocked SSH through 443 port by blocking CONNECT method of the HTTP Proxy.
A second solution is to use a false 'login' page. Using proxy can ask for password, this is normaly asked by ...
- 141
4
votes
Captive portal DNS tunneling
There are various easy to find solutions for dns tunnel so it does not make sense to describe specific solutions in detail.
But, this does not mean that these solutions will work with captive portals....
- 198k
4
votes
X windows security: VNC and X server vs xpra
The "normal" way to use remote X11 is to have the X11 server run not on your server, but on the machine which is physically in front of the user. Then use ssh to do X11 forwarding, so that the ...
- 172k
4
votes
Can a Government block a specific app traffic, even with a VPN running?
In theory one could use heuristics to guess the kind of traffic. A typical example is flow analysis where one analysis the size, direction and timing of transferred data because various protocols and ...
- 198k
4
votes
Accepted
Are there any feasible ways to block the stunnel utility at the network level?
Since you exclude SSL interception (i.e. no certs can be installed) and also exclude any kind of traffic pattern analysis there is not much left. What could be tried is analyzing the TLS handshake ...
- 198k
4
votes
Accepted
Is the same key used for Authorization and Encryption? (SSH Tunnel)
TL;DR: In SSH your private key is not used for encryption at all, it's only used to prove who you are. Each new connection to the server will establish a different encryption session key.
Here are ...
- 58.8k
3
votes
Does a Server connecting to port 3544 pose an increased risk
Recommendation at:
https://www.stigviewer.com/stig/windows_7/2013-10-01/finding/V-17449
Is to block outbound IPv6 UDP 3544 for Windows Servers
Reason:
IPv6 transition technologies, which tunnel ...
- 31
3
votes
Accepted
Does AH in tunneling mode provide encryption?
AH mode doesn't provide encryption, it only makes the traffic it tamper-proof. It doesn't matter whether it's in transport or tunnel mode. If you need encryption then ESP is what you need.
That ...
- 46
3
votes
Security concerns with external MySQL access using tunnelling
Well, assuming you are using SSH to access the server anyway, that tunneling is effectively already in place. I would suggest doing a few things to prevent unauthorized access to your VPS:
Give a non-...
- 196
3
votes
Accepted
Detecting DNS tunneling
DNS does not use ICMP. It uses UDP (and rarely TCP) port 53.
The firewall/router the captive portal contols either does not block that port or it is the DNS server and is responding.
All other ...
- 3,946
3
votes
Are VPN tunnels really completely private?
These claims are ridiculous.
There are plenty of threat models that aren't covered by VPN services like this:
VPN server is compromised.
Other network infrastructure within the VPN server's network ...
- 135k
3
votes
How does a network admin block the reverse SSH in company?
The first question should be why are users / admins using reverse ssh tunnels. I worked at a company that had a really poorly implemented VPN for remote management, that only allowed connectivity to a ...
- 31
3
votes
Can a Government block a specific app traffic, even with a VPN running?
If the VPN connection is properly setup such that all data goes through it is not possible to block specific apps since there is no way to know what data is sent through the VPN connection.
Without ...
- 446
3
votes
Accepted
Is it sensible to tunnel TLS traffic over another TLS?
If I understand it correctly, this is a rough network diagram of your situation:
You're saying A and B want to talk, but they can't directly so they use Relay. You are thinking of having A set up an ...
- 32.7k
3
votes
Accepted
What's the security concern of browsers using the HTTP CONNECT method?
The CONNECT method leaves the TCP connection at a different state than it originally was; unlike other HTTP request, the CONNECT method is stateful, it is always the last HTTP request that can happen ...
- 31.4k
3
votes
Can I use a VPN to access services only available to a specific network?
VPN, yes; Nord VPN no
A VPN allows you to tunnel your traffic such that it will appear that you are physically on the destination network. If said library was hosting a vpn, your idea would work ...
- 7,692
2
votes
Should I tunnel multiple TCP connections through a TLS/SSL tunnel or use TLS/SSL for each connection?
You should use multiple TLS connection. However, you should make sure that your application opens the multiple connection using TLS abbreviated handshake and session resumption possibly with session ...
- 31.4k
2
votes
Accepted
Transfer of packets in a VPN connection
How are the packets transferred between a website and the computer that's using a VPN?
A VPN is just another connection. Your computer makes a connection to the VPN server, and the VPN server makes a ...
- 53.5k
2
votes
How does a network admin block the reverse SSH in company?
Luajit via Suricata IDPS provides some advanced mechanisms for controlling SSH as well as SSL/TLS tunnels to prevent proxy subversion, reverse shells, et al.
Check out this rather thorough, albeit ...
- 19k
2
votes
Tunneling over a HTTP subfolder?
TL;DR That proxy does not allow for tunneling. And you have a firewall that parses the HTTP requests, likely to disallow HTTP tunneling altogether. You're pretty much limited to GET and POST.
Since ...
- 5,857
2
votes
Webserver port tunneling security - security options
I'm afraid that you have already failed at the first hurdle since you are using HTTP everywhere. This means that you are pushing unencrypted login traffic over the Internet which is subject to ...
- 7,132
Only top scored, non community-wiki answers of a minimum length are eligible