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44

The usual tool for this is something called netcat. It's available in most Linux distros, and may even be installed by default in some (the command is nc). There are even ports for Windows, but nearly every antivirus package on the planet considers it deeply suspicious due it's use in malware which makes it hard to download and use.


42

It is a reasonable concern as there are tools that accomplish arp poisoning (spoofing) that allow you convince computers that you are the gateway. An example and relatively easy to use tool would be ettercap that automates the whole process. It will convince their computer that you are the gateway and sniff the traffic, it will also forward packets so ...


21

Yes, but it's not just because of your use of Telnet and your weak passwords, it's because of your attitude towards security. Good security comes in layers. You should not assume that because you have a good firewall, your internal security can be weak. You should assume that at some point in time, your firewall will be compromised, the workstations will ...


15

The tool to use is probably the windows ports of netcat.


14

This is what the 'screen' utility was invented for. Although I've used it mainly on Linux, there's absolutely no reason a port for your OS couldn't exist. It's part of the gnu tool set, and I haven't found a port, but one probably exists (or could).


13

When you say, on the bash shell, I am assuming this shell is running on the computer at the locations you mention. If you have SSH to some other host and ran ftp/telnet then these answers are irrelevant. can my coworker see it? Maybe, if your are both connected to a hub, if you are on a switch and he hasn't done anything evil like arp poisoning he ...


13

Yes it is a big concern as with some simple ARP poisoning you can normally sniff the LAN without being physically at the right switch port, just as in the good old hub days - and it's very easy to do too.


13

Here is a shell one-liner: echo -e "\x38\x01\x00\x00\x00\x00\x00\x00\x00" | timeout 10 nc -u openvpnserver.com 1194 | cat -v if there is an openvpn on the other end the output will be @$M-^HM--LdM-t|M-^X^@^@^@^@^@@$M-^HM--LdM-t|M-^X^@^@^@^@^@@$M-^HM--LdM-t|M-^X... otherwise it will just be mute and timeout after 10 seconds or display something ...


13

You are looking for a program called netcat. It is the swiss army knife of network utilities. You can tell it to listen on any arbitrary port as well as many other things.


11

Unless you really need telnet for some unusual reason, don't use telnet for this. SSH can provide the same environment, but provides encryption and plenty of other useful features. Telnet on the other hand provides no security at all, passwords are sent in plain text. Certainly, I wouldn't even consider allowing telnet outside of a home lan or other secure ...


11

You can install OpenSSL for Windows, and use it to connect to servers using SSL. Type this in the command line: openssl s_client -connect pop.gmail.com:995 By the way, Gmail's SMTP servers require authentication too (unless you're connecting from anotehr known mail server), so you'd better start with something simpler.


10

1) on host a: telnet listen 12345 $ ls | nc -l -p 12345 Depends on the distro and netcat version, you may not need -p option. 2) on host b: telnet host_a 12345 $ telnet host_a 12345 1159.rar 12030.mp4 123.mp4 124.mp4 129 129.bak ...


9

Telnet provides the ability to communicate with a service, nothing more nothing less. If that service happens to be a shell on a server, great, but it's not always. I often use telnet to send a malformed HTTP request manually, or to manually run commands against an SMTP server. SSH is way more than just a way of logging on to a server remotely. It can be ...


8

Nope. Either you're walking them through installing the telnet client native to Windows, or you're having them install Putty or a similar app. The functionality was deemed a security risk and so was turned off.


8

Don't make a telnet server. Install OpenSSH and you'll have a secure version of telnet which you can use to run remote commands - all without having to write a single line of code.


8

Best security practices for telnet is to not use it. Failing that, restrict everything you possibly can, what IPs it will talk to, who can login, etc. I have no idea what you mean by "combine the 2".


8

You can use pam_succeed_if in your /etc/pam.d/telnet or similar file: auth required pam_suceed_if.so user = ${telnet_user} quiet Where ${telnet_user} is the user allowed to use telnet. But, if you weren't aware, telnet is a Bad Thing. The allowed account's details can easily be sniffed and may enable other people to use the account. Really do you SSH if ...


8

Ick. You're going to have to base64 encode the attachment and create the MIME headers. Rather than generating a new message "on the fly" each time, it would probably be easier just to email yourself a very short example message from a "real" email program (leveraging the work that the people who wrote it did to put the attachment into the proper encoding ...


7

It looks like this is not possible with the Windows telnet service. I even tested running the service under the local system account with "interact with desktop" enabled, but that did not work (which is fine as it would have serious security implications). As an alternative to using telnet, I would recommend PsExec. PsExec is part of the SysInternal tools ...


7

Anyone with the ability to sniff the traffic between you and the site that you have connected to can potentially read your ftp password, or any data that travels unencrypted. So, realistically, all scenarios above will be possible, with the following notes: 1) Your co-worker would either have to be able to tap into your external network, or be able to ...


7

Some are: Legacy -- ssh/sftp isn't always an option Laziness / Ignorance Not everything needs to be secured (For example, downloads of Adobe Acrobat) For telnet, security could be provided in another way, for instance, IPSec encapsulation


7

The software listening on port 11211 doesn't support IPv6. Since localhost is an entry in the hosts file that tries an IPv6 address first, you only fail back to IPv4 after IPv6 fails. You can solve the issue by either getting the software updated (or properly configured to listen on IPv6 if it's an option in the config file) or changing your command to ...


7

You've got a small learning curve ahead of you: A command line / command prompt is simply one way that programs present themselves to the user; via a CLI (command line interface). The other way is through a GUI (graphical user interface). Many programs have both kinds: you can choose which to use, graphical or command-line. It's a matter of taste. An ...


7

It looks like your mailserver is only listening on localhost and not your public IP: tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN Change the configuration so it's listening on the proper IP. Be sure to do this properly as mis-configured mail servers are the norm.


7

This appears to be working as expected however, whatever is running on [otherIPAddress]:9300 is not expecting Hello World\n so it dropped the connection.


7

Did you try to 'telnet' way? I.e.: Ctrl+] telnet> quit


7

Why use telnet? It's an old, old, very insecure technology. Use OpenSSH instead - it's much more secure, offers much more functionality (tunneling, file copy, key authentication to name a few), and comes by default with nearly every linux distro out there.


6

When connected to the monitor via telnet, anything that you type will be interpreted as a command by the monitor itself. You can view the full list of commands in the QEMU Emulator User Documentation, one of which is quit (or q for short). To disconnect the telnet session you need to first use the telnet escape key which is Ctrl-] and then you can type quit ...


6

Screen. You will probably need to install it with apt-get install screen or similar, but once you have it, it's quite straight forward. Use screen to start it, and you will be given a bash or sh shell, use that to run your batch job, then use Ctrl+A followed by Ctrl+D to detach from the session. You may then log out, and can reattach at any time using screen ...



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