Update: UltraVNC 1.4.3.6 and UltraVNC SC 1.4.3.6: https://forum.uvnc.com/viewtopic.php?t=37885
Important: Please update to latest version before to create a reply, a topic or an issue: https://forum.uvnc.com/viewtopic.php?t=37864

Join us on social networks and share our announcements:
- Website: https://uvnc.com/
- GitHub: https://github.com/ultravnc
- Mastodon: https://mastodon.social/@ultravnc
- Bluesky/AT Protocol: https://bsky.app/profile/ultravnc.bsky.social
- Facebook: https://www.facebook.com/ultravnc1
- X/Twitter: https://x.com/ultravnc1
- Reddit community: https://www.reddit.com/r/ultravnc
- OpenHub: https://openhub.net/p/ultravnc

UltraVNC Reverse/ Screen Locked

Post Reply
zago123
Posts: 3
Joined: 2018-01-05 13:04

UltraVNC Reverse/ Screen Locked

Post by zago123 »

Hi guys,

i need help,

I'm using ultravnc on my computers, I use it in reverse mode, that is, when I'm on some problem client computer, I have a program that calls the server through the reverse vnc. the server it is in listen mode.

The problem is this, every time I open some application that needs administrator permission the vnc blocks the screen for me and I can not move.

In what options do I change this?

thanks
User avatar
Rudi De Vos
Admin & Developer
Admin & Developer
Posts: 6867
Joined: 2004-04-23 10:21
Contact:

Re: UltraVNC Reverse/ Screen Locked

Post by Rudi De Vos »

Cause:
UAC block applications with lower permission to send data to higher.
Workaround
1) If winvnc is started with "runas admin" you are able to control the admin apps, but still you are not able to press the UAC prompt on the secure desktop.
2) if winvnc is started as service you are able to control the admin apps and you can access the secure desktop

In most cases 1) will do as the user is in front to help the grant access to admin apps.
zago123
Posts: 3
Joined: 2018-01-05 13:04

Re: UltraVNC Reverse/ Screen Locked

Post by zago123 »

:surprise: UAC low here, and not work, in vnc reverse will have permission problem vnc blocks the screen for e and i can not move.
User avatar
slx
Posts: 1
Joined: 2018-02-26 18:57

Re: UltraVNC Reverse/ Screen Locked

Post by slx »

Hello,

I had something like this. In the left upper corner a red windows appears with something like: UltraVVNC running as application does not have permission to acces UAC protected windows
So my windows 10 instance also uses autologin and switch it off is no option.

The solution in my case was:
- open cmd.exe with adminstrator privledges
- start C:\Windows\System32\UserAccountControlSettings.exe
A Window arrises with 4 level. The 3rd is Windows 10 Pro standard. Lower this to 2nd level of the floor.
When you now start vncviewer and you start an application that need elevated rights, the screen is not blacked out with the red Windows in the upper left corner.

So actually I seems this has nothing to do with vnc-server configuration.

Hope this helps,
Post Reply