Ubuntu Security Notice USN-4134-3
March 24, 2020
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 19.10
– Ubuntu 18.04 LTS
– Ubuntu 16.04 LTS
IBus could allow local users to capture key strokes of other locally logged
– ibus: Intelligent Input Bus – core
USN-4134-1 fixed a vulnerability in IBus. The update caused a regression in
some Qt applications and the fix was subsequently reverted in
USN-4134-2. The regression has since been resolved and so this update fixes
the original vulnerability.
We apologize for the inconvenience.
Original advisory details:
Simon McVittie discovered that IBus did not enforce appropriate access
controls on its private D-Bus socket. A local unprivileged user who
discovers the IBus socket address of another user could exploit this to
capture the key strokes of the other user.
The problem can be corrected by updating your system to the following
Ubuntu 18.04 LTS:
Ubuntu 16.04 LTS:
After a standard system update you need to reboot your computer to make
all the necessary changes.