CVE-2017-17520

DISPUTED tools/url_handler.pl in TIN 2.4.1 does not validate strings
before launching the program specified by the BROWSER environment variable,
which might allow remote attackers to conduct argument-injection attacks
via a crafted URL. NOTE: a third party has reported that this is
intentional behavior, because the documentation states “url_handler.pl was
designed to work together with tin which only issues shell escaped absolute
URLs.”