The CSSFontFaceSrcValue::fetch function in core/css/CSSFontFaceSrcValue.cpp in the Cascading Style Sheets (CSS) implementation in Blink, as used in Google Chrome before 46.0.2490.71, does not use the CORS cross-origin request algorithm when a font's URL appears to be a same-origin URL, which allows remote web servers to bypass the Same Origin Policy via a redirect.
https://src.chromium.org/viewvc/blink?revision=199364&view=revision
https://security.gentoo.org/glsa/201603-09
https://code.google.com/p/chromium/issues/detail?id=512678
http://www.ubuntu.com/usn/USN-2770-2
http://www.ubuntu.com/usn/USN-2770-1
http://www.securitytracker.com/id/1033816
http://www.securityfocus.com/bid/77071
http://www.debian.org/security/2015/dsa-3376
http://rhn.redhat.com/errata/RHSA-2015-1912.html
http://googlechromereleases.blogspot.com/2015/10/stable-channel-update.html