Okular can be tricked into executing local binaries via specially crafted
PDF files.
This binary execution can require almost no user interaction.
No parameters can be passed to those local binaries.
We have not been able to identify any binary that will cause actual damage,
be it in the hardware or software level, when run without parameters.
We remain relatively confident that for this issue to do any actual damage,
it has to run a binary specially crafted. That binary must have been deployed
to the user system via another method, be it the user downloading it directly
as an email attachment, webpage download, etc. or by the system being already
compromised.