CVE-2019-9797

Las imágenes de origen cruzado se pueden leer infringiendo la política del mismo origen al exportar una imagen después de utilizar createImageBitmap para leer la imagen y luego renderizar la imagen de mapa de bits resultante dentro de un elemento canvas. Esta vulnerabilidad afecta a Firefox, versiones anteriores a 66.

USN-3918-1 fixed vulnerabilities in Firefox. This update provides the corresponding updates for Ubuntu 14.04 LTS. 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 via application crash, denial of service via successive FTP authorization prompts or modal alerts, trick the user with confusing permission request prompts, obtain sensitive information, conduct social engineering attacks, or execute arbitrary code. A mechanism was discovered that removes some bounds checking for string, array, or typed array accesses if Spectre mitigations have been disabled. If a user were tricked in to opening a specially crafted website with Spectre mitigations disabled, an attacker could potentially exploit this to cause a denial of service, or execute arbitrary code. It was discovered that Upgrade-Insecure-Requests was incorrectly enforced for same-origin navigation. An attacker could potentially exploit this to conduct man-in-the-middle attacks. Various other issues were also addressed.