Ultra VNC server hangs when vb6 exe sends a SHELL command

[asfixiao]

Hi, please excuse if the issue was already studied but I can not find a post about it..

When using a Ultra VNC Server in Windows 8.1. 64 bits and a client UltraVNC viewer connects, if the remote user runs a menu option from an own VB6 program that sends a SHELL statement for a *.BAT file, the service Server hangs and there is no way to restart connections. You finally must restart the server!

Could anyone help me to solve, any ideas...

Thx a lot in advance

[Rudi De Vos]

I need to be able to repeat it.
What actions are require to simulate it.

Did you already tried to disable the system hook, server option.

[asfixiao]

Thx Rudi, in fact that's happening in one customer and I just repeat it a few minutes ago. How about disable the system hook?

[asfixiao]

the system hook mark in properties form, server, is not enabled.
You only need an VB6 exe program sending a SHELL statement, I'm trying to reproduce using a VBScript and then will share with you..

[asfixiao]

Hi, it can be reproduced running once connected a simple VB script like this: (sometimes it takes some executions, sometime at the first...)

cmd.cmd:
dir *.* /s
exit

vnc_crash.vbs:
set objshell = createobject("wscript.shell")
objshell.run "cmd.cmd",vbNormal