By not quoting the argument, an attacker with the ability to add files
to the repository could pass arbitrary arguments to the highlight
command, in particular, the --plug-in argument which can lead to
arbitrary command execution.
This patch adds simple argument quoting.
# found (for example) on EPEL 6.
#
# This is for version 2
-exec highlight --force -f -I -X -S $EXTENSION 2>/dev/null
+exec highlight --force -f -I -X -S "$EXTENSION" 2>/dev/null
# This is for version 3
-#exec highlight --force -f -I -O xhtml -S $EXTENSION 2>/dev/null
+#exec highlight --force -f -I -O xhtml -S "$EXTENSION" 2>/dev/null