An issue was discovered in Squiz Matrix CMS 5.5.0 prior to 5.5.0.3, 5.5.1 prior to 5.5.1.8, 5.5.2 prior to 5.5.2.4, and 5.5.3 prior to 5.5.3.3 where a user can trigger arbitrary unserialization of a PHP object from a packages/cms/page_templates/page_remote_content/page_remote_content.inc POST parameter during processing of a Remote Content page type. This unserialization can be used to trigger the inclusion of arbitrary files on the filesystem (local file inclusion), and results in remote code execution.

An issue was discovered in Squiz Matrix CMS 5.5.0 prior to 5.5.0.3, 5.5.1 prior to 5.5.1.8, 5.5.2 prior to 5.5.2.4, and 5.5.3 prior to 5.5.3.3 where a user can trigger arbitrary unserialization of a PHP object from a packages/cms/page_templates/page_remote_content/page_remote_content.inc POST parameter during processing of a Remote Content page type. This unserialization can be used to trigger the inclusion of arbitrary files on the filesystem (local file inclusion), and results in remote code execution.