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Posted to dev@tomcat.apache.org by ma...@apache.org on 2019/04/18 18:36:06 UTC

[tomcat] branch 8.5.x updated: Security hardening. Avoid loading user specified classes.

This is an automated email from the ASF dual-hosted git repository.

markt pushed a commit to branch 8.5.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git


The following commit(s) were added to refs/heads/8.5.x by this push:
     new 2e23cb4  Security hardening. Avoid loading user specified classes.
2e23cb4 is described below

commit 2e23cb4221e828f1f462a6b4a58f96762fd4a5e7
Author: Mark Thomas <ma...@apache.org>
AuthorDate: Thu Apr 18 19:32:57 2019 +0100

    Security hardening. Avoid loading user specified classes.
    
    The user is trusted so loading a user specified class should be safe but
    given it isn't necessary to load the class, avoid doing so. Reported by
    Coverity scan.
---
 .../apache/catalina/manager/ManagerServlet.java    |  56 ++++++-----
 .../org/apache/tomcat/util/IntrospectionUtils.java |  22 ++++
 .../apache/tomcat/util/TestIntrospectionUtils.java | 112 +++++++++++++++++++++
 webapps/docs/changelog.xml                         |   4 +
 4 files changed, 169 insertions(+), 25 deletions(-)

diff --git a/java/org/apache/catalina/manager/ManagerServlet.java b/java/org/apache/catalina/manager/ManagerServlet.java
index dc22ae5..3174cb5 100644
--- a/java/org/apache/catalina/manager/ManagerServlet.java
+++ b/java/org/apache/catalina/manager/ManagerServlet.java
@@ -66,6 +66,7 @@ import org.apache.coyote.ProtocolHandler;
 import org.apache.coyote.http11.AbstractHttp11Protocol;
 import org.apache.tomcat.util.Diagnostics;
 import org.apache.tomcat.util.ExceptionUtils;
+import org.apache.tomcat.util.IntrospectionUtils;
 import org.apache.tomcat.util.modeler.Registry;
 import org.apache.tomcat.util.net.SSLContext;
 import org.apache.tomcat.util.net.SSLHostConfig;
@@ -1131,21 +1132,31 @@ public class ManagerServlet extends HttpServlet implements ContainerServlet {
             writer.println(smClient.getString("managerServlet.resourcesAll"));
         }
 
-        Class<?> clazz = null;
-        try {
-            if (type != null) {
-                clazz = Class.forName(type);
-            }
-        } catch (Throwable t) {
-            ExceptionUtils.handleThrowable(t);
-            log("ManagerServlet.resources[" + type + "]", t);
-            writer.println(smClient.getString("managerServlet.exception",
-                    t.toString()));
-            return;
-        }
+        printResources(writer, "", global, type, smClient);
+
+    }
 
-        printResources(writer, "", global, type, clazz, smClient);
 
+    /**
+     * List the resources of the given context.
+     *
+     * @param writer Writer to render to
+     * @param prefix Path for recursion
+     * @param namingContext The naming context for lookups
+     * @param type Fully qualified class name of the resource type of interest,
+     *  or <code>null</code> to list resources of all types
+     * @param clazz Unused
+     * @param smClient i18n support for current client's locale
+     *
+     * @deprecated Use {@link #printResources(PrintWriter, String,
+     *             javax.naming.Context, String, StringManager)}
+     *             This method will be removed in Tomcat 10.x onwards
+     */
+    @Deprecated
+    protected void printResources(PrintWriter writer, String prefix,
+            javax.naming.Context namingContext,
+            String type, Class<?> clazz, StringManager smClient) {
+        printResources(writer, prefix, namingContext, type, smClient);
     }
 
 
@@ -1156,27 +1167,23 @@ public class ManagerServlet extends HttpServlet implements ContainerServlet {
      * @param namingContext The naming context for lookups
      * @param type Fully qualified class name of the resource type of interest,
      *  or <code>null</code> to list resources of all types
-     * @param clazz The resource class or <code>null</code> to list
-     *  resources of all types
      * @param smClient i18n support for current client's locale
      */
     protected void printResources(PrintWriter writer, String prefix,
                                   javax.naming.Context namingContext,
-                                  String type, Class<?> clazz,
+                                  String type,
                                   StringManager smClient) {
-
         try {
             NamingEnumeration<Binding> items = namingContext.listBindings("");
             while (items.hasMore()) {
                 Binding item = items.next();
-                if (item.getObject() instanceof javax.naming.Context) {
-                    printResources
-                        (writer, prefix + item.getName() + "/",
-                         (javax.naming.Context) item.getObject(), type, clazz,
-                         smClient);
+                Object obj = item.getObject();
+                if (obj instanceof javax.naming.Context) {
+                    printResources(writer, prefix + item.getName() + "/",
+                            (javax.naming.Context) obj, type, smClient);
                 } else {
-                    if ((clazz != null) &&
-                        (!(clazz.isInstance(item.getObject())))) {
+                    if (type != null && (obj == null ||
+                            !IntrospectionUtils.isInstance(obj.getClass(), type))) {
                         continue;
                     }
                     writer.print(prefix + item.getName());
@@ -1192,7 +1199,6 @@ public class ManagerServlet extends HttpServlet implements ContainerServlet {
             writer.println(smClient.getString("managerServlet.exception",
                     t.toString()));
         }
-
     }
 
 
diff --git a/java/org/apache/tomcat/util/IntrospectionUtils.java b/java/org/apache/tomcat/util/IntrospectionUtils.java
index aa96446..e3d6c76 100644
--- a/java/org/apache/tomcat/util/IntrospectionUtils.java
+++ b/java/org/apache/tomcat/util/IntrospectionUtils.java
@@ -452,6 +452,28 @@ public final class IntrospectionUtils {
         return result;
     }
 
+
+    public static boolean isInstance(Class<?> clazz, String type) {
+        if (type.equals(clazz.getName())) {
+            return true;
+        }
+
+        Class<?>[] ifaces = clazz.getInterfaces();
+        for (Class<?> iface : ifaces) {
+            if (isInstance(iface, type)) {
+                return true;
+            }
+        }
+
+        Class<?> superClazz = clazz.getSuperclass();
+        if (superClazz == null) {
+            return false;
+        } else {
+            return isInstance(superClazz, type);
+        }
+    }
+
+
     // -------------------- Get property --------------------
     // This provides a layer of abstraction
 
diff --git a/test/org/apache/tomcat/util/TestIntrospectionUtils.java b/test/org/apache/tomcat/util/TestIntrospectionUtils.java
new file mode 100644
index 0000000..64864f6
--- /dev/null
+++ b/test/org/apache/tomcat/util/TestIntrospectionUtils.java
@@ -0,0 +1,112 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.tomcat.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.apache.catalina.core.StandardContext;
+
+public class TestIntrospectionUtils {
+
+    // Test for all the classes and interfaces in StandardContext's type hierarchy
+
+    @Test
+    public void testIsInstanceStandardContext01() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.core.StandardContext"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext02() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.util.LifecycleMBeanBase"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext03() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.util.LifecycleBase"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext04() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "java.lang.Object"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext05() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.Lifecycle"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext06() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.JmxEnabled"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext07() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "javax.management.MBeanRegistration"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext08() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.catalina.Container"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext09() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "org.apache.tomcat.ContextBind"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext10() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "javax.management.NotificationEmitter"));
+    }
+
+
+    @Test
+    public void testIsInstanceStandardContext11() {
+        Assert.assertTrue(IntrospectionUtils.isInstance(
+                StandardContext.class, "javax.management.NotificationBroadcaster"));
+    }
+
+    // And one to check that non-matches return false
+
+
+    @Test
+    public void testIsInstanceStandardContext12() {
+        Assert.assertFalse(IntrospectionUtils.isInstance(
+                StandardContext.class, "com.example.Other"));
+    }
+}
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 3354ad8..b8a0685 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -75,6 +75,10 @@
         Fix a potential resource leak when a JNDI lookup returns an object of an
         in compatible class. Identified by Coverity scan. (markt)
       </fix>
+      <scode>
+        Refactor <code>ManagerServlet</code> to avoid loading classes when
+        filtering JNDI resources for resources of a specified type. (markt)
+      </scode>
     </changelog>
   </subsection>
 </section>


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