HTTP 403 error – PowerShell Remoting, Different Domains and Proxies

On my day to day work I use Nagios monitoring software. I want to add some custom SQL Server scripts to enrich the monitoring, and to accomplish this I will need to:

  • Find a folder
  • Create a sub folder
  • Copy bunch of file
  • edit a ini file to verify/add new entries

all of this for every single host on my entire estate. Obviously (for me 🙂 ) I decided to use PowerShell!

Hold your horses!

Yes, calm down. I’m working on a client where the network it’s anything but simple. As far as I know they have 10 domains and few of them have trust configured, but even those that have, is not in both ways… so I didn’t expect an easy journey to get the task done.

Side note: For those thinking how I can live without PowerShell, I can’t! But,  the majority of my time using PowerShell is with SQL Server, mainly using SMO (with the help of dbatools), which means I haven’t struggle that much until now.

“…WinRM client received an HTTP status code of 403…”

Ok, here we go!

PowerShell Remoting and different domains…

….needs different credentials. This is a requirement when using ip address.
If we try to run the following code:

$DestinationComputer = '10.10.10.1'
Invoke-Command -ScriptBlock { Get-Service *sql* } -ComputerName $DestinationComputer

we will get the following error message:

Default authentication may be used with an IP address under the following conditions: the transport is HTTPS or the destination is in the TrustedHosts list, and explicit credentials are provided.

First, I add the destination computer to my TrustedHosts. We can do this in two ways:

Using Set-Item PowerShell cmdlet

Set-Item WSMan:\localhost\Client\TrustedHosts "10.10.10.1"

Or using winrm executable:

winrm s winrm/config/client '@{TrustedHosts="10.10.10.1"}'

Note: You can use “*” (asterisk) to say all remote hosts are trusted. Or just a segment of IPs like “10.10.10.*”.

But, there is another requirement like the error message says “…and explicit credentials are provided.”. This means that we need to add, and in this case I really want to use, a different credential so I have modified the script to:

$DestinationComputer = '10.10.10.1'
Invoke-Command -ScriptBlock { Get-Service *sql* } -ComputerName $DestinationComputer -Credential domain2\user1

Now I get prompted for the user password and I can… get a different error message (*sigh*):

[10.10.10.1] Connecting to remote server 10.10.10.1 failed with the following error message : The WinRM client received an HTTP status code of 403 from the remote WS-Management service. For more information, see the

about_Remote_Troubleshooting Help topic.

+ CategoryInfo : OpenError: (10.10.10.1:String) [], PSRemotingTransportException

+ FullyQualifiedErrorId : -2144108273,PSSessionStateBroken

This one was new for me so I jumped to google and started searching for this error message. Unfortunately all the references I found are to solve an IIS problem with SSL checkbox on the website like this example.

Clearly this is not the problem I was having.

Proxies

I jumped into PowerShell slack (you can ask for an invite here and join more than 3 thousand professionals) and ask for help on #powershell-help channel.
In the meantime, I continued my search and found something to do with proxies in the The dreaded 403 PowerShell Remoting blog post.
This actually could help, but I don’t want to remove the existing proxies from the remote machine. I had to find another way to do it.

Returning to Slack, Josh Duffney (b | t) and Daniel Silva (b | t) quickly prompted to help me and when I mentioned the blog post on proxies, Daniel has shown to me the PowerTip PowerShell Remoting and HTTP 403 Error that I haven’t found before (don’t ask me why…well, I have an idea, I copy & paste the whole error message that’s why).

ProxyAccessType

The answer, for my scenario, is the ProxyAccessType parameter. As it says on the help page, this option “defines the access type for the proxy connection”. There are 5 different options AutoDetect, IEConfig, None, NoProxyServer and WinHttpConfig.

I need to use NoProxyServer to “do not use a proxy server – resolves all host names locally”. Here is the full code:

$DestinationComputer = '10.10.10.1'
$option = New-PSSessionOption -ProxyAccessType NoProxyServer
Invoke-Command -ScriptBlock { Get-Service *sql* } -ComputerName $DestinationComputer -Credential domain2\user1 -SessionOption $option

This will:

  • create a new PowerShell Session option (line 2) with New-PSSessionOption cmdlet saying that -ProxyAccessType is NoProxyServer.
  • Then, just use the $option as the value of -SessionOption parameter on the Invoke-Command.

This did the trick! Finally I was able to run code on the remote host.

Thanks for reading.

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