Escalation of privilege with Javascript: URL as home page — Mozilla

Security researcher Mariusz Mlynski reported that an attacker able to convince a potential victim to set a new home page by dragging a link to the “home” button can set that user’s home page to a javascript: URL. Once this is done the attacker’s page can cause repeated crashes of the browser, eventually getting the script URL loaded in the privileged about:sessionrestore context.