Local files or privileged URLs in pages can be opened into new tabs — Mozilla

Security researcher Jann Horn reported that when Mozilla Foundation Security Advisory 2015-25 was fixed in Firefox 37, an error was made that caused the fix to not be applied to Firefox 38, effectively causing the bug to be unfixed in Firefox 38 (and Firefox ESR38) once it shipped. As Armin Ebert reported for that issue, opening hyperlinks on a page with the mouse and specific keyboard key combinations could allow a Chrome privileged URL to be opened without context restrictions being preserved. This could allow for local files or resources from a known location to be opened with local privileges, bypassing security protections.