Security problem: Locked cinnamon is not-locked!

[Perlover]

Hello!

I have Mint 18.3
Cinnamon 3.6.7

Computer: ASUS UX305C
This computer has micro-hdmi output
Video resolution of ASUS UX305C: 3200x1800 (i think it's related problem)

What happens: i have locked it by Ctrl + Alt + Del
At display of ultrabook i see locked screen and i have locked it.
But if i connect it to monitor (1920x1080) to micro-HDMI-HDMI cable there i see small locked window (left up corner, 1/3 part) and other space - not locked screen
And i had connect mouse to UX305C. I don't know important this or not.

I made video: https://www.dropbox.com/s/j01s2fl9mpp3m ... 4.mp4?dl=0

It's high security vulnerability! Locked computer now is not already locked computer

Please help to close this hole!

Thanks!

Perlover

[karlchen]

<bump> No-one interested in the reported issue? </bump>

[MtnDewManiac]

<bump> No-one interested in the reported issue? </bump>

Was it reported in the proper place? According to http://linuxmint-troubleshooting-guide. ... where.html , for Cinnamon, that place is here:
http://github.com/linuxmint/Cinnamon

Regards,
MDM

[karlchen]

Hm. Actually, the reported behaviour reminded me of some bug which had affected the Ubuntu Unity Desktop once in the past.
Similar or same way of getting around the lock screen.
I had hoped someone might remember that case.
I am not even sure if Unity itself was the culprit, or some other system module.
Plus, I had hoped some Mint 18.3 Cinnamon users might chime in and report whether they can reproduce the problem.
My LM 18.1 Cinnamon system is a desktop machine and has got only 1 monitor, not connected via micro-HDMI.