A brute force attack uses a large volume of requests/responses from the same source or destination IP address to break into a system. The attacker employs a trial-and-error method to guess the response to a challenge or a request.
The Vulnerability Protection profile on the firewall includes signatures to protect you from brute force attacks. Each signature has an ID, Threat Name, Severity and is triggered when a pattern is recorded. The pattern specifies the conditions and interval at which the traffic is identified as a brute-force attack; some signatures are associated with another child signature that is of a lower severity and specifies the pattern to match against. When a pattern matches against the signature or child signature, it triggers the default action for the signature.
To enforce protection:
Attach the vulnerability profile to a security rule. See Set Up Antivirus, Anti-Spyware, and Vulnerability Protection. Install content updates that include new signatures to protect against emerging threats. See Install Content and Software Updates.

Related Documentation