Design document functions which receive a user http request object may expose authorization or session cookie headers of the user who accesses the document. These design document functions are: *   list *   show *   rewrite *   update An attacker can leak the session component using an HTML-like output, insert the session as an external resource (such as an image), or store the credential in a _local document with an "update" function. For the attack to succeed the attacker has to be able to insert the design documents into the database, then manipulate a user to access a function from that design document. Workaround: Avoid using design documents from untrusted sources which may attempt to access or manipulate request object's headers