FTP: Nested Request
This protocol anomaly triggers when it detects two or more FTP commands without an intermittent reply. FTP clients normally wait for a server reply before moving to their next command, so this can indicate a denial-of-service (DoS) or a tunneling attempt.
References
srx-branch-12.3
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-branch-19.4
vsrx-19.4
mx-12.3
mx-19.4
vmx-19.4
mx-19.3
vsrx3bsd-19.4
srx-19.4
vsrx-12.3
vmx-19.3
vsrx-19.2
srx-12.3