A "data:" URL loaded in a new tab did not inherit the Content Security Policy (CSP) of the original page, allowing for bypasses of the policy including the execution of JavaScript. In prior versions when "data:" documents also inherited the context of the original page this would allow for potential cross-site scripting (XSS) attacks. This vulnerability affects Firefox < 57.
Una URL "data:" cargada en una nueva pestaña no hereda la política de seguridad de contenido (CSP) de la página original, permitiendo la omisión de la política, incluyendo la ejecución de código JavaScript. Las versiones anteriores, cuando los documentos "data:" también heredaban el contexto de la página original, permitirían ataques Cross-Site Scripting (XSS) potenciales. Esta vulnerabilidad afecta a las versiones anteriores a la 57 de Firefox.
USN-3477-1 fixed vulnerabilities in Firefox. The update caused search suggestions to not be displayed when performing Google searches from the search bar. This update fixes the problem. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, read uninitialized memory, obtain sensitive information, bypass same-origin restrictions, bypass CSP protections, bypass mixed content blocking, spoof the addressbar, or execute arbitrary code. It was discovered that javascript: URLs pasted in to the addressbar would be executed instead of being blocked in some circumstances. If a user were tricked in to copying a specially crafted URL in to the addressbar, an attacker could potentially exploit this to conduct cross-site scripting attacks. It was discovered that exported bookmarks do not strip script elements from user-supplied tags. If a user were tricked in to adding specially crafted tags to bookmarks, exporting them and then opening the resulting HTML file, an attacker could potentially exploit this to conduct cross-site scripting attacks. Various other issues were also addressed.