From the Gentoo alert:
Miroslav Lichvar discovered that the "xdg-open" and "xdg-email" shell
scripts do not properly sanitize their input before processing it.
A remote attacker could entice a user to open a specially crafted link
with a vulnerable application using Xdg-Utils (e.g. an email client),
resulting in the execution of arbitrary code with the privileges of the
user running the application.
