Published: 13 September 2019
A flaw was discovered in ibus in versions before 1.5.22 that allows any unprivileged user to monitor and send method calls to the ibus bus of another user due to a misconfiguration in the DBus server setup. A local attacker may use this flaw to intercept all keystrokes of a victim user who is using the graphical interface, change the input method engine, or modify other input related configurations of the victim user.
From the Ubuntu security team
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.
CVSS 3 base score: 7.1
Launchpad, Ubuntu, Debian
|Ubuntu 18.04 LTS (Bionic Beaver)||
|Ubuntu 16.04 ESM (Xenial Xerus)||
|Ubuntu 14.04 ESM (Trusty Tahr)||
Does not exist
The ibus D-Bus socket address contains a long random guid making discovery of this address by another user unlikely.
this was reverted in 4134-2 because of a regression, see LP bug