ntp released an announcement on 26th April 2016, describing 4 low and 7 medium severity vulnerabilities, as listed below:
FortiOS versions 5.4.1, 5.4.0, 5.2.8 and below are vulnerable to only CVE-2016-1550.
Upgrade to FortiOS version
- 5.2.9 or above
- 5.4.2 or above
- or 5.6.0