Indico legacy contribution export cache poisoning discloses restricted metadata

Indico is a feature-rich event management system. Indico 3.3.3 through 3.3.13 incorrectly uses the ambient web-session user instead of the user supplied to Contribution.can_manage when checking inherited event contribution-management permission. A low-privileged user can induce a privileged user to request a crafted legacy contribution export and cause speaker or author email addresses and contribution access-control entries to be stored in an API cache entry retrievable with less privilege. This issue was fixed in Indico 3.3.14.