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From: Martin Vaeth <martin@mvath.de>
Subject: [gentoo-user] Re: Switching default tmpfiles and faster internet coming my way.
Date: Sun, 6 Dec 2020 16:57:21 -0000 (UTC)
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Michael Orlitzky <mjo@gentoo.org> wrote:
>
> Why are you focusing on /tmp and /var/tmp?

Because only world-writable directories are the ones which
can be exploited unless the tmpfiles.conf author does
something malevolent or extremely stupid.

> To pick a relevant example

relevant?

> If that was a 'Z' entry, or if it created another portage:portage
> directory beneath /var/cache/eix

In other words: If the completely harmless example would have
been replaced by an intentionally malevolent one, this could do harm.
With this logic, installing systemd-opentmpfiles is the same
security risk: If its ebuild would just contain the line
chmod -R /*
everybody could easily become root on your system when you install it.