FTP: User Name Dictionary Attack
This signature detects attempts to enumerate FTP user names through a Dictionary Attack. Attackers can attempt multiple connections using a dictionary of user names and record the server response. An attacker could then use the list of valid FTP user names to perform a brute-force password attack and possibly gain access to the victim's server.
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