Cotonti 1.0.0 (master branch, commit f43f1fc3) is vulnerable to Cross-Site Request Forgery in the administration rights handler. In system/admin/admin.rights.php, the rights update action ('a=update') modifies group access rights (including via cot_auth_add_group) without calling cot_check_xg to validate the anti-CSRF token.
CWE-352