Powershell keeps scrambling the security settings and SID

I am trying to modify the security of SCMANAGER, but do not seems to get the result i am hoping for:

$SID = "S-1-5-21-5126416528-1234567890-3447268803-1234"
# $SCMANParams = "D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(A;;CCLCRPRC;;;$($SID))S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)"
# $SetPermissionCommand = @"
# CMD.exe /C sc sdset scmanager '"$($SCMANParams)"'
# "@
# Invoke-Expression -command $SetPermissionCommand

This results in:

D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(**A;;CC;;;S-1-15-3-1024-528118966-3876874398-709513571-1907873084-3598227634-9941730060-274077788-3990600260**)S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)

While i am trying to achieve:

cmd.exe /c "sc sdset scmanager D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(A;;CCLCRPRC;;;S-1-5-21-5126416528-1234567890-3447268803-1234)S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)"

If i run the code interactive, both ways work. If i run the script via GPO (Startup script), i get the scrambled result…

Hey Killerbe,

Could you further explain why you think PowerShell is the reason for this? Any other salient details you can provide?

It seems you’re really running cmd under the hood. and simply invoking it with Invoke-Expression. Furthermore, you mentioned it works when you run it interactively but not via gpo. This would imply that the command ran in the first block works interactively, which means something else would be at play (like the GPO).

Also I want to make sure I, as well as others, fully understand the problem. When you try via GPO to set this, the actual SDDL string that is set on the SC manager is:

D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(**A;;CC;;;S-1-15-3-1024-528118966-3876874398-709513571-1907873084-3598227634-9941730060-274077788-3990600260**)S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)

You expect this (which works just running it interactively):

D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(A;;CCLCRPRC;;;S-1-5-21-5126416528-1234567890-3447268803-1234)S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)

I’m hung up on the term ‘scramble’. It seems like only a part of the SDDL string is not expected, specifically:

# The unexpected section of SDDL string
(**A;;CC;;;S-1-15-3-1024-528118966-3876874398-709513571-1907873084-3598227634-9941730060-274077788-3990600260**)
# Should actually be:
(A;;CCLCRPRC;;;S-1-5-21-5126416528-1234567890-3447268803-1234)

Is that correct? I’m assuming the SID being different is expected potentially. the bigger issue being the other part of the SDDL string missing stuff and adding asterick characters. because I remove that bit from the corresponding ‘expected output’, the output is exactly the same, so its not really ‘scrambled’.

Have you confirmed the GPO’s code is indeed matching what you do interactively? Is this just running a PS1 file? Have you tried just not doing Invoke-Expression and just doing a batch script to rule out PS? Based on the information provided I can’t really conclude that PS is the issue.

1 Like

A couple other quick thoughts.

  1. the ** - I noticed there was ending **… was this added perhaps by mistake when you were entering the data and trying to bold something?
  2. If 1 is true, then maybe it has something to do with timing and it not being able to properly resolve. You might investigate other ways to set that via GPO, or through a different means. Perhaps it’s trying to validate parts of that string and isn’t able too, thus not properly completing it. maybe a login script instead of a startup script?

The ** ** are added by the Code formatter here.
The origional code is
‘“A;;CC;;;S-1-15-3-1024-528118966-3876874398-709513571-1907873084-3598227634-9941730060-274077788-3990600260”’

I haven’t seen the code formatter do that. It’s possible the bold hotkey was hit while that block of code was highlighted.

In any case I provided a possible idea as to why, and a possible path forward (though it’s really more related to GPOs and not PS).

Thx for the response.
I doubt this is caused by GPO as it merely calling the PS1 file with the code.
The result is that the SID is scrambled, and some permissions are not set.
the expected permissions would be CCLCRPRC, while only CC is being set.
The SID is way longer then the SID applied in the PS1 file.

Hey Killerbe:

Just to make sure you did uncomment all your code when you are calling it in your ps1 via gpo? If you forgot to uncomment any part of your code in the actual PS1 file that gets called, that could explain it. What if you’re calling it and its null, and that other SID was just something thta happened to be on that service object already? Code works interactively for me when I uncomment… but when I ran the code as is, not uncommenting (but updated the SID of course), i got a success message, but the SDDL string that retunrs using sc.exe sdshow scmanager didn’t change at all.

EDIT: To clarify, if you left it as is, in the first code, the script would just basically do nothing. Just for giggles I ran something like this:

$SID = "S-1-5-21-5126416528-1234567890-3447268803-1234"
# $SCMANParams = "D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CC;;;AC)(A;;CCLCRPRC;;;$($SID))S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)"
 $SetPermissionCommand = @"
 CMD.exe /C sc sdset scmanager '"$($SCMANParams)"'
 "@
Invoke-Expression -command $SetPermissionCommand

I really haven’t used the sc.exe command much but the result of that is basically empty $SCmanParams var. I ran that and it just did nothing. I was expecting it to null out the SDDL string tbh.

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