Cross-site scripting (XSS) vulnerability in the Layout module's SEO configuration in Liferay Portal 7.4.3.70 through 7.4.3.73, and Liferay DXP 7.4 update 70 through 73 allows remote attackers to inject arbitrary web script or HTML via the `_com_liferay_layout_admin_web_portlet_GroupPagesPortlet_backURL` parameter.