CVE-2020-15678

Al volver a recorrer las capas gráficas mientras se desplaza, es posible que un iterador pueda convertirse en no válido, resultando en un potencial uso de la memoria previamente liberada. Esto ocurre porque la función APZCTreeManager::ComputeClippedCompositionBounds no siguió las reglas de invalidación del iterador. Esta vulnerabilidad afecta a Firefox versiones anteriores a 81, Thunderbird versiones anteriores a 78.3, y Firefox ESR versiones anteriores a 78.3

The Mozilla Foundation Security Advisory describes this flaw as: When recursing through graphical layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free. This occurs because the function `APZCTreeManager::ComputeClippedCompositionBounds` did not follow iterator invalidation rules.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. This update upgrades Firefox to version 78.3.0 ESR. Issues addressed include bypass, cross site scripting, integer overflow, spoofing, and use-after-free vulnerabilities.