IBM Cloud Docs
OWASP evaluation example

OWASP evaluation example

The following example calculates the OWASP request threat score for an incoming request.

The OWASP managed ruleset configuration is as follows:

  • OWASP Anomaly Score Threshold: High - 25 and higher
  • OWASP Paranoia Level: PL3
  • OWASP Action: Managed Challenge

This table shows the progress of the OWASP ruleset evaluation:

Progress of the OWASP ruleset evaluation
Rule ID Paranoia level Rule matched? Rule score Cumulative threat score
0
...1813a269 PL3 Yes +5 5
...ccc02be6 PL3 No 5
...96bfe867 PL2 Yes +5 10
...48b74690 PL1 Yes +5 15
...3297003f PL2 Yes +3 18
...317f28e1 PL1 No 18
...682bb405 PL2 Yes +5 23
...56bb8946 PL2 No 23
...e5f94216 PL3 Yes +3 26
(...) (...) (...) (...) (...)
...f3b37cb1 PL4 (not evaluated) 26

Final request threat score: 26

Since 26 >= 25 — that is, the threat score is greater than the configured score threshold — CIS applies the configured action (Managed Challenge). If you configured a score threshold of Medium - 40 and higher, CIS wouldn't apply the action, since the request threat score would be lower than the score threshold (26 < 40).

Sampled logs in Security Events would display the following details for the example incoming request handled by the OWASP Core Ruleset.

In sampled logs, the rule associated with requests mitigated by the CIS OWASP Core Ruleset is the last rule in this managed ruleset: 949110: Inbound Anomaly Score Exceeded, with rule ID 6179ae15870a4bb7b2d480d4843b323c. To get the scores of individual rules contributing to the final request threat score, expand Additional logs in the event details.