------------------------------------------------------------------------ Microsoft Edge Fetch API allows setting of arbitrary request headers ------------------------------------------------------------------------ Yorick Koster, January 2017 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ It was found that the Fetch API in Microsoft Edge allows websites to set arbitrary HTTP request headers, including the Content-Length, and Host headers. Amongst others, a malicious website can use this issue to bypass the same origin policy, read HTTP response headers, or initiate arbitrary HTTP requests from the victim's browser (HTTP request smuggling). ------------------------------------------------------------------------ See also ------------------------------------------------------------------------ - CVE-2017-0140 - MS17-007: Cumulative Security Update for Microsoft Edge (4013071) ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully tested on Microsoft Edge version 38.14393.0.0 (EdgeHTML 14.14393). ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ Microsoft released MS17-007 that fixes this vulnerability. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://www.securify.nl/advisory/SFY20170101/microsoft_edge_fetch_api_allows_setting_of_arbitrary_request_headers.html
