Once a LUKS device is unlocked it is accessible without the password - so I think what is happening is that you are unlocking the device via Thunar and then it remains unlocked, so even though Thunar has forgotten the password, it does not need it to access the device anymore. You need to relock the LUKS device then to prevent further access. This seems more like a UX issue where it is not clear what the expectation may be for the user rather than a security issue.
** Information type changed from Private Security to Public -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1879095 Title: Thunar can open LUKS device in spite of "Forget Password immediately" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunar/+bug/1879095/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
