CVE-2014-8090

El analizador REXML en Ruby 1.9.x anterior a 1.9.3 patchlevel 551, 2.0.x anterior a 2.0.0 patchlevel 598, y 2.1.x anterior a 2.1.5 permite a atacantes remotos causar una denegación de servicio (consumo de CPU y memoria) a través de un documento XML manipulado que contiene una cadena vacía en una entidad que se utiliza en un número grande de referencias de entidad anidadas, también conocido como un ataque de expansión de entidad XML (XEE). NOTA: esta vulnerabilidad existe debido a una solución incompleta para CVE-2013-1821 y CVE-2014-8080.

Due to unrestricted entity expansion, when reading text nodes from an XML document, the REXML parser in Ruby can be coerced into allocating extremely large string objects which can consume all of the memory on a machine, causing a denial of service. Will Wood discovered that Ruby incorrectly handled the encodes() function. An attacker could possibly use this issue to cause Ruby to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. Due to an incomplete fix for 100% CPU utilization can occur as a result of recursive expansion with an empty String. When reading text nodes from an XML document, the REXML parser in Ruby can be coerced into allocating extremely large string objects which can consume all of the memory on a machine, causing a denial of service.