A stored cross-site scripting (XSS) vulnerability exists in FUEL-CMS 1.5.1 that allows an authenticated user to upload a malicious .pdf file which acts as a stored XSS payload. If this stored XSS payload is triggered by an administrator it will trigger a XSS attack.
A host header attack vulnerability exists in FUEL CMS 1.5.0 through fuel/modules/fuel/config/fuel_constants.php and fuel/modules/fuel/libraries/Asset.php. An attacker can use a man in the middle attack such as phishing.
An issue was discovered in FUEL CMS 1.4.7. There is a escalation of privilege vulnerability to obtain super admin privilege via the "id" and "fuel_id" parameters.