flatpak: Flatpak is a system for building, distributing, and running sandboxeddesktop applications on Linux

Flatpak is a system for building, distributing, and running sandboxeddesktop applications on Linux. in versions before 1.10.9, 1.12.9, 1.14.6,and 1.15.8, a malicious or compromised Flatpak app could execute arbitrarycode outside its sandbox. Normally, the `--command` argument of `flatpakrun` expects to be given a command to run in the specified Flatpak app,optionally along with some arguments. However it is possible to insteadpass `bwrap` arguments to `--command=`, such as `--bind`. It's possible topass an arbitrary `commandline` to the portal interface`org.freedesktop.portal.Background.RequestBackground` from within a Flatpakapp. When this is converted into a `--command` and arguments, it achievesthe same effect of passing arguments directly to `bwrap`, and thus can beused for a sandbox escape. The solution is to pass the `--` argument to`bwrap`, which makes it stop processing options. This has been supportedsince bubblewrap 0.3.0. All supported versions of Flatpak require at leastthat version of bubblewrap. xdg-desktop-portal version 1.18.4 will mitigatethis vulnerability by only allowing Flatpak apps to create .desktop filesfor commands that do not start with --. The vulnerability is patched in1.15.8, 1.10.9, 1.12.9, and 1.14.6.

Where it's fixed