Design document functions that receive a user HTTP request object may expose authorization or session cookie headers of the user who accesses the document. These design document functions include `list`, `show`, `rewrite`, and `update`. An attacker can leak the session component using an HTML-like output, insert the session as an external resource, or store the credential in a local document with an `update` function. For the attack to succeed, the attacker must be able to insert the design documents into the database and then manipulate a user to access a function from that design document.