Solution : https://service.sap.com/sap/support/notes/853878 (SAP Service marketplace login required)
Key words : 
cl_http_utility=>http_whitelist_ep_css_url  cl_http_utility=>http_whitelist_sap_exiturl  cl_http_utility=>http_whitelist_wda_resume_url, potentially execute unknown javascript code, add addition security feature, additional note assistent corrections, <html> <header> <css src=, central framework provided functionality, abap server received information, externally received themeroot url, function cl_http_utility=>check_http_whitelist, execute javascript files
Related Notes : 
       
| 1274793 | BSP: HTTP WhiteList Check fails for port entries | 
| 1261193 | |
| 1245560 | Composite SAP Note : XSS Documentation | 
| 891232 | BSP Security Relevant Changes | 
| 887322 | Whitelist checks of sap-exit URL |