CVE-2017-8923

La función zend_string_extend en el archivo Zend/zend_string.h en PHP hasta de la versión 7.1.5 no impide cambios en los objetos de cadena que resultan en una longitud negativa, lo que permite a los atacantes remotos causar una denegación de servicio (bloqueo de aplicación) o posiblemente tener otro impacto no especificado explotando el uso de scripts .= con una cadena larga.

An integer overflow vulnerability in PHP can lead to a buffer overflow when constructing extremely long strings with the ".=" operator. In unusual circumstances, this could be used by an attacker to cause an application to crash or possibly have other consequences.

USN-5300-1 fixed vulnerabilities in PHP. This update provides the corresponding updates for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. It was discovered that PHP incorrectly handled certain scripts. An attacker could possibly use this issue to cause a denial of service. It was discovered that PHP incorrectly handled certain inputs. An attacker could possibly use this issue to cause a denial of service, or possibly obtain sensitive information. It was discovered that PHP incorrectly handled certain scripts with XML parsing functions. An attacker could possibly use this issue to obtain sensitive information.