Block "]]>" in createCDataSection

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 9dfe1b6aff51b606a7eef0ba47b3a8d2309763d5..06fc17552b892b38b1e884123c5e740b08181cdb 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -806,6 +806,10 @@ PassRefPtr<CDATASection> Document::createCDATASection(const String& data, Except
         es.throwDOMException(NotSupportedError);
         return 0;
     }
+    if (data.find("]]>") != WTF::notFound) {
+        es.throwDOMException(InvalidCharacterError, "String cannot contain ']]>' since that is the end delimiter of a CData section.");
+        return 0;
+    }
     return CDATASection::create(this, data);
 }