This vulnerability is fixed by an upgrade to the FPGA firmware. Customers are advised to follow the procedure outlined in the Firmware Upgrade section of the Cisco Firepower 4100/9300 FXOS CLI Configuration Guide.
This procedure works for FXOS Software Releases 2.2.2 or later. A customer on an earlier release should upgrade to Software Release 2.2.2 (or later) or contact the Cisco TAC for assistance.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.