Feature: #107771 - Make rel attribute in external links configurable
See forge#107771
Description
For security reasons, external links that open in a new window should be
generated with rel="noopener" to prevent the opened page to have access
to the originating document via JavaScript's Window. object.
TYPO3's default behavior is to add rel="noreferrer" to all such links,
which automatically implies rel="noopener" and even is more strict and
not even sends the HTTP "Referer" header to the opened page. This behavior could
be too strict and unwanted for some website owners.
This feature introduces a new TypoScript option config.
to define the rel attribute for external links. The default behavior
stays rel="noreferrer" but by setting the TypoScript property to
noopener, all external links are generated with rel="noopener"
instead.
The feature respects existing individual settins per link. All rel="noopener"
and rel="noreferrer" from other sources are kept.
Impact
A new TypoScript configuration option config.
is available and can be set to "noreferrer" (default) to "noopener".
This setting affects all external links with target="_.