POP3: Request Error Invalid State
This protocol anomaly triggers when it detects a POP3 client in an invalid state due to the sequence of the commands it has issued. This can indicate an attacker using command line access to a POP3 server, as well as a denial-of-service attack 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