How can we add a custom header using the 'msg' value from a ModSecurity rule, for all rules triggered? I'm basically trying to track the ModSec block reason at an edge point (Varnish) based on Apache's response.
For example, I would like:
SecRule REQUEST_URI "/modsectest" "log,deny,status:406,phase:1,t:none,id:9084310,msg:'ModSec Log Test'"
To add a 'X-ModSec-Block' response header with the value 'ModSec Log Test' in this case. I understand this might be better suited with setenv + mod_headers due to blocks being done at different phases, and found Modsecurity : Creating a new Request Header from SecRule which seems similar to this scenario, just that it's not quite working out for me. Any help is greatly appreciated!
