| Description: | Flatpak is a system for building, distributing, and running sandboxed
desktop 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 arbitrary code outside its sandbox. Normally, the `--command`
argument of `flatpak run` expects to be given a command to run in the
specified Flatpak app, optionally along with some arguments. However
it is possible to instead pass `bwrap` arguments to `--command=`, such
as `--bind`. It's possible to pass an arbitrary `commandline` to the
portal interface `org.freedesktop.portal.Background.RequestBackground`
from within a Flatpak app. When this is converted into a `--command`
and arguments, it achieves the same effect of passing arguments
directly to `bwrap`, and thus can be used for a sandbox escape. The
solution is to pass the `--` argument to `bwrap`, which makes it stop
processing options. This has been supported since bubblewrap 0.3.0.
All supported versions of Flatpak require at least that version of
bubblewrap. xdg-desktop-portal version 1.18.4 will mitigate this
vulnerability by only allowing Flatpak apps to create .desktop files
for commands that do not start with --. The vulnerability is patched
in 1.15.8, 1.10.9, 1.12.9, and 1.14.6.
|
