dheb's questions

I don't really have a generic code issue. I'm here to ask a newbie TCP communication question - I need it in order to continue my PowerShell project.

According to what I already know, during the ssh information exchange, only the ssh server is port forwarded. Let's say, that it works on port 22 and only ssh server is forwarded on that port. Well then how does ssh server respond to the client?

The router only blocks inbound connections without a specific rule. A client send a packet to a ssh server (router doesn't block the outbound request), then ssh server claims it (server doesn't block the inbound connection, because of the previous forward), processes the command, and sends back the output. But how does that happen? The client blocks all the inbound requests, because port 22 is not port forwarded.

It would be really great if someone could answer this question, sorry if it's not well-explained, but I tried my best. Once again this is a newbie question so please notice that I don't have the vocabulary range for that topic.

Recently i was trying to research deeper into running remote commands from windows to windows. It can be easy with ssh, ftp - but I wanted it to run the commands without knowing the password either username, just local ip and computer name and maybe some opened firewall ports.

I used couple commands that some people suggested me to:

• wmic
• powershell remote commands
• winrs
• psexec

However some errors appeared and now i can't continue my work.

WMIC

When trying to run node wmic command this error often appeared

ERROR: 
Description = RPC server is unavailable

It happened every time when i was trying to run this command. I've even tested this on couple computers. Let me know if i have to use some setup commands on remote computer for this to work

Powershell

I've did everything microsoft docs said. Even though i didn't work. I've tried getting the ps session, entering it etc.

This is the command that i used for invoking a command:

Invoke-Command -ComputerName DHEB -ScriptBlock {Get-UICulture}

It executed this error:

[DHEB] Connecting to remote server DHEB failed with the following error message : WinRM cannot process the request.
The following error with errorcode 0x8009030e occurred while using Negotiate authentication: A specified logon session
does not exist. It may already have been terminated.
 Possible causes are:
  -The user name or password specified are invalid.
  -Kerberos is used when no authentication method and no user name are specified.
  -Kerberos accepts domain user names, but not local user names.
  -The Service Principal Name (SPN) for the remote computer name and port does not exist.
  -The client and remote computers are in different domains and there is no trust between the two domains.
 After checking for the above issues, try the following:
  -Check the Event Viewer for events related to authentication.
  -Change the authentication method; add the destination computer to the WinRM TrustedHosts configuration setting or
use HTTPS transport.
 Note that computers in the TrustedHosts list might not be authenticated.
   -For more information about WinRM configuration, run the following command: winrm help config. For more
information, see the about_Remote_Troubleshooting Help topic.
    + CategoryInfo          : OpenError: (DHEB:String) [], PSRemotingTransportException
    + FullyQualifiedErrorId : 1312,PSSessionStateBroken

WinRS

Winrs command also didn't turn out well. Desktop-VAPJUPI is online and winrs is installed on the pc. However it still didn't work

Command:

winrs -r:"DESKTOP-VAPJUPI" cmd.exe

Output:

Winrs error:
C:\Users\matis>The WinRM client cannot process the request. If the authentication scheme is different from Kerberos, or if the client computer is not joined to a domain, then HTTPS transport must be used or the destination machine must be added to the TrustedHosts configuration setting. Use winrm.cmd to configure TrustedHosts. Note that computers in the TrustedHosts list might not be authenticated. You can get more information about that by running the following command: winrm help config.

PsExec

The last command that i used is psexec. It is very stable and very useful, however it didn't work for me.

Command:

PsExec.exe \DESKTOP-VAPJUPI -e -i -nobanner cmd.exe

Output:

Couldn't access DESKTOP-VAPJUPI:
The network path was not found.

Make sure that the default admin$ share is enabled on DESKTOP-VAPJUPI.

I tried sharing whole C:\ disk on Desktop-VAPJUPI, but it still didn't work. Let me know how do I share the default for admin$

As you can see non of the commands worked. I don't know if I'm doing everything wrong either my pcs are retarted, or maybe the whole thing that i want to do is impossible.

And yes I know that I can setup anonymous login for ftp or ssh keys for passwordless login, however I don't want to do that for some reason.

Also I would be happy if someone told me if there are any more ways to open unauthorized access to pc

Any answers are appreciated, thanks