Closing because of missing user response.
Missing Accept header
Davdroid does not send the HTTP Accept header, which triggers a lot of rules when used with a service behind mod_security (or other web application firewalls).
Thus, davdroid should send the Accept header and advertise which Content-Types are accepted.
Thanks for the suggestion. Because DAVdroid only accepts XML for
REPORTrequests and iCal/VCard files for
GET, it should send appropriate
Great! Thanks for the fast fix.