Fat Free CRM before 0.12.1 does not restrict XML serialization, which allows remote attackers to obtain sensitive information via a direct request, as demonstrated by a request for users/1.xml, a different vulnerability than CVE-2013-7224.
https://github.com/fatfreecrm/fat_free_crm/wiki/Fixing-security-vulnerabilities-%2827th-Dec-2013%29
https://github.com/fatfreecrm/fat_free_crm/issues/300