UltraVNC 1.4.2.0 and UltraVNC SC 1.4.2.0 - Feedbacks

[sockd]

I understand that this is security related.
But due to our settings (we run a kind of kiosk mode without a logged in user) we urgently need the file transfer while no user is logged in.
Would it be possible to set the username to use for file transfer in the .ini file?

[sockd]

Maybe to be more precise:
User xyz is logged in, but we change "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell" from explorer.exe to our own .exe ...
So for some software the system looks like if there´s no user logged in ...
Up to 1.3.8.2 FT worked with FTUserImpersonation=1, but with 1.4.2.0 it seems to not work any longer ...
And like I asked in the post before, maybe it´s possible to add a user to the .ini so it will use this credentials for FT?

[Rudi De Vos]

In that case there is a possible soloution, try
[admin]
alternate_shell = own.exe

When this parameter is set and explorer.exe is not found we use own.exe instead.

Please give it a try

[sockd]

I´ll test it, but I think it won´t work...

I´ll try to describe how we are working:
- in "Shell" (where normally "explorer.exe" is set) we set to "PassChecker.exe"
- When System starts, "PassChecker.exe" is started
- Then you have ~ 1 Minute to enter the technician password
- If password is not entered or wrong a "StartApplication.bat" is started which starts all needed processes - after that "PassChecker.exe" closes itself
- If password is correct a "StartAdministration.bat" is started and "explorer.exe" is started - "PassChecker.exe" remains in memory
- As soon as the technician clicks on "Logoff" (provided by "PassChecker.exe"), "explorer.exe" and "PassChecker.exe" are closed

So most of the times, the "Shell" is not running ...

[Rudi De Vos]

startApplication.bat" is started which starts all needed processes

It don't have to be a real shell, but some exe that is started by the user you want to impersonate.
You can use any needed process for it.

VNC copy the security token from the exe it doesn't have to be a shell

You can also runas /user:my notepad.exe and use notepad.exe for it

[sockd]

Perfect. Thank you for the detailed explanation.
Will start/continue with the tests tomorrow.

[Tartao]

Hi there!
my first message here, even if it's some years I use UltraVNC without problems!

It's some days I'm trying to stop a nasty IP (125.70.16.120) to try to connect to may machine.
I had version 1.2.30, yes quite old, and was experimenting with QuerySetting=2 and AuthHosts parameters:

Code: Select all

AuthHosts=?:?125.70.16.120:+37:+192.168.1
QuerySetting=2
QueryTimeout=10
QueryAccept=0
QueryIfNoLogon=0

Then yesterday evening I decided to upgrade to last version, 1.4.2.0
But I think there's a bug, because each and every time I open and close the settings window,
QuerySetting value is resetting to 4, it really seems hardcoded!

Also, in the settings windows this parameter is not present, as well as the Host lists parameter.
Plus, this window seems that doesn't read the actual running config, so the checkbox is always unmarked

The problem is that 4 set this behaviour (as from https://uvnc.com/docs/uvnc-server/69-ultravncini.html):
Define on how to react on the (-,?,+) from the Authhosts.
0="+:Accept, ?:Accept, -:Query"
1="+:Accept, ?:Accept, -:Reject"
2="+:Accept, ?:Query, -:Reject [Default]"
3="+:Query, ?:Query, -:Reject"
4="+:Query, ?:Reject, -:Reject"

This means that I now have to confirm every allowed connection.
Instead I wanted to allow my own connections with the +,
and query that specific IP and also every other IP with the ?

I now have a workaround:
- manually stop the windows service uvnc_service
- update ultravnc.ini
- manually start the windows service uvnc_service

I also have to remember not to save the configuration using the Admin Properties window.

Is it possible to fix these issue, or maybe there's some other workaround?
Let me know if you need some more info!

Best regards,
Andrea - Italy

[duncanh]

Hi there,

I have a slight issue with version 1.4.2.0 of the Viewer - when I exit the application, the "Windows Security" settings screen and a "File Explorer" window are opened.

I am using Windows 10 Pro (version 22H2: build 19045.3086)
I ran the "UltraVNC_1_4_20_X64_Setup.exe" to install the product. I am also using the SecureVNCPlugin64.dsm (version 2.4.1.0).

The issue doesn't appear to impact the functionality of the tool but it is a bit annoying

[Ludovic]

Please use the latest UltraVNC or UltraVNC SC releases:
- viewforum.php?f=56