A vulnerability in the FTP Representational State Transfer Application Programming Interface (REST API) for Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass FTP malware detection rules and download malware over an FTP connection. Cisco Firepower System Software is affected when the device has a file policy with malware block configured for FTP connections. More Information: CSCuv36188 CSCuy91156. Known Affected Releases: 5.4.0.2 5.4.1.1 5.4.1.6 6.0.0 6.1.0 6.2.0. Known Fixed Releases: 6.0.0.