WordPress before 5.2.4 is vulnerable to poisoning of the cache of JSON GET requests because certain requests lack a Vary: Origin header.
{ "binaries": [ { "binary_name": "wordpress", "binary_version": "4.4.2+dfsg-1ubuntu1" }, { "binary_name": "wordpress-l10n", "binary_version": "4.4.2+dfsg-1ubuntu1" }, { "binary_name": "wordpress-theme-twentyfifteen", "binary_version": "4.4.2+dfsg-1ubuntu1" }, { "binary_name": "wordpress-theme-twentyfourteen", "binary_version": "4.4.2+dfsg-1ubuntu1" }, { "binary_name": "wordpress-theme-twentysixteen", "binary_version": "4.4.2+dfsg-1ubuntu1" } ] }
{ "binaries": [ { "binary_name": "wordpress", "binary_version": "4.9.5+dfsg1-1" }, { "binary_name": "wordpress-l10n", "binary_version": "4.9.5+dfsg1-1" }, { "binary_name": "wordpress-theme-twentyfifteen", "binary_version": "4.9.5+dfsg1-1" }, { "binary_name": "wordpress-theme-twentyseventeen", "binary_version": "4.9.5+dfsg1-1" }, { "binary_name": "wordpress-theme-twentysixteen", "binary_version": "4.9.5+dfsg1-1" } ] }