fallbackBehavior

What WAF should do if it fails to completely parse the JSON body. The options are the following:

• EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.

• MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.

• NO_MATCH - Treat the web request as not matching the rule statement.

If you don't provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

Example JSON: { "UriFragment": { "FallbackBehavior": "MATCH"} }

WAF parsing doesn't fully validate the input JSON string, so parsing can succeed even for invalid JSON. When parsing succeeds, WAF doesn't apply the fallback behavior. For more information, see JSON body in the WAF Developer Guide.