CVE-2017-6590

An issue was discovered in network-manager-applet (aka
network-manager-gnome) in Ubuntu 12.04 LTS, 14.04 LTS, 16.04 LTS, and
16.10. A local attacker could use this issue at the default Ubuntu login
screen to access local files and execute arbitrary commands as the lightdm
user. The exploitation requires physical access to the locked computer and
the Wi-Fi must be turned on. An access point that lets you use a
certificate to login is required as well, but it’s easy to create one.
Then, it’s possible to open a nautilus window and browse directories. One
also can open some applications such as Firefox, which is useful for
downloading malicious binaries.