There is currently a feature in VistA that will block access to a user after multiple failed login attempts. The feature is available but often not turned on in many VistA installations.
The action required to turn this on is as follows: Edit Site IP lockout [XU SITE LOCKOUT]
The VistA Security TWG highly recommends that all users of open source VistA turn on and use this feature. Please email any questions to VSTWG@osehra.org.
Michael Henderson, DSS, Inc.
Joseph Ortman, U.S. Department of Veterans Affairs