Using statistical analysis to generate exception rules that allow legitimate messages to pass through application proxies and gateways

摘要

A security gateway receives messages rejected by a message filter based on a set of rules. The security gateway also receives attributes of the rejected messages that triggered the rules. The security gateway maintains frequencies with which the messages with a particular attribute were rejected by the rules. The security gateway finds rejected messages or attributes having a high frequency of occurrence. Since messages or attributes having a high frequency of occurrences are more likely to represent legitimate requests rather than malicious attacks, the security gateway generates exception rules, which would allow messages that have similar attributes to pass through the gateway.