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Posts Tagged ‘terminal’

Windows Terminal Server: “Too many connections”

January 16th, 2013 No comments

There is one backdoor which can be used. Since Windows 2003 there is a little known feature which helps in a “too many connections” situation. The Remote Desktop client offers an option which allows you to connect to the console. This gives you a 3rd connection. If someone is logged into the console you have to have the sufficient permissions then the session will be logged out and you can log in. If nobody is logged into the console it will let you log in.

Start -> Run -> CMD
cd Program FilesTerminal Services Client
mstsc -v:x.x.x.x /console

Share a Console using “screen”

July 16th, 2008 No comments

This is too good to risk losing so I’m reproducing the recipe here.
For my needs, I was able to skip a few steps by using root and by using screen session ids.
Here is the original article (with a couple of minor changes):

Assume user jsmith wants to share his terminal session with remote user bjones for training or troubleshooting purposes, but does not want to use VNC or other full-blown GUI remote control access.

Requirements:
– GNU Screen
– Local account on host computer for remote user (i.e. bjones requires local account)

1. Install screen

sudo apt-get install screen

2. Set the screen binary (/usr/bin/screen) setuid root. By default, screen is installed with the setuid bit turned off, as this is a potential security hole.

sudo chmod +s /usr/bin/screen sudo chmod 755 /var/run/screen

3. The host starts screen in a local xterm, using the command screen -S SessionName. The -S switch gives the session a name, which makes multiple screen sessions easier to manage.

screen -S screen-test

4. The remote user (bjones) uses SSH to connect to the host computer (jsmith).

ssh [email protected]

5. The host (jsmith) then has to allow multiuser access in the screen session via the command CTRL-A :multiuser on (all ‘screen’ commands start with the screen escape sequence, CTRL-A).

CTRL-A :multiuser on

6. Next, the host (jsmith) must grant permission to the remote user (bjones) to access the screen session using the commadn CTRL-A :acladd user_name where user_name is the remote user’s login ID.

CTRL-A :acladd bjones

7. The remote user can now connect to the hosts ‘screen’ session. The syntax to connect to another user’s screen session is screen -x host_username/sessionname.

screen -x jsmith/screen-test