Fix #2589 (#2901)

Co-authored-by: Tatu Saloranta <tatu.saloranta@iki.fi>

release-notes/CREDITS-2.x

@@ -872,3 +872,8 @@ Kaki King (kingkk9279@g)
 Jon Anderson (Jon901@github)
   * Reported #2544: java.lang.NoClassDefFoundError Thrown for compact profile1
    (2.9.10.2)
+
+Bartosz Baranowski (baranowb@github)
+  * Reported #2589: `DOMDeserializer`: setExpandEntityReferences(false) may not prevent
+   external entity expansion in all cases
+ (2.9.10.7)

release-notes/VERSION-2.x

@@ -6,6 +6,10 @@ Project: jackson-databind
 
 2.9.10.7 (not yet released)
 
+#2589: `DOMDeserializer`: setExpandEntityReferences(false) may not prevent
+  external entity expansion in all cases
+ (reported by Bartosz B)
+
 #2854: Block one more gadget type (javax.swing, CVE-2020-xxx)
  (reported by Yangkun(ICSL))
 

src/main/java/com/fasterxml/jackson/databind/ext/DOMDeserializer.java

@@ -39,6 +39,14 @@ public abstract class DOMDeserializer<T> extends FromStringDeserializer<T>
             // 14-Jul-2016, tatu: Not sure how or why, but during code coverage runs
             //   (via Cobertura) we get `java.lang.AbstractMethodError` so... ignore that too
         }
+
+        // [databind#2589] add two more settings just in case
+        try {
+            parserFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+        } catch (Throwable t) { } // as per previous one, nothing much to do
+        try {
+            parserFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+        } catch (Throwable t) { } // as per previous one, nothing much to do
         DEFAULT_PARSER_FACTORY = parserFactory;
     }