Feature #5466


detect: allow alert-then-pass logic

Added by Victor Julien about 1 year ago. Updated 4 months ago.

Target version:


Currently pass acts as a noalert rule that stops further alerting.

Some usecases have been identified in which ppl want a "alert then pass" in a single rule. Currently they are forced to express this in 2 rules, an alert rule and a pass rule, where the action order and or priorities needs to be setup such that the alert rule is evaluated first.

We do support the following: alert .... (bypass; ...).

I think we could extend the config rule keyword for this.

E.g. something like:
alert ... (config:logging disable, type alert, scope flow;)

The behavior would still need to log the current alert, so it needs a bit of thought on how to express this.

Actions #1

Updated by Jason Ish 10 months ago

One thought, a companion keyword to noalert: alert.

pass ftp a b -> c d (msg:"LOG This as a reason why the flow passed"; alert; ...;)
Actions #2

Updated by Shivani Bhardwaj 9 months ago

I like Jason's idea. Other thoughts:

1. config:action pass, type alert, scope flow Not sure if adding more than logging subsystem to config would be too much pain though.
2. new keyword to define next action post match. action:pass which sets the rule's action to the defined action after executing the current defined action on the rule. (perhaps some other name to avoid confusion with the logs)

Actions #3

Updated by Juliana Fajardini Reichow 5 months ago

As a first solution, think of achieving this as a configuration option to log `PASS` rules to the alert eve type.

Actions #4

Updated by Juliana Fajardini Reichow 5 months ago

  • Target version changed from TBD to 7.0.0-rc2
Actions #5

Updated by Juliana Fajardini Reichow 4 months ago

  • Target version changed from 7.0.0-rc2 to 8.0.0-beta1

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