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log4j/CVE-2021-44228-1.patch
starlet-dx dbce122982 fix CVE-2021-44228 
(cherry picked from commit 3ec2ef9b5f83e82fdcbd0390038e8a92aa1cdabc)
2021-12-11 15:10:28 +08:00

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From 755e2c9d57f0517a73d16bfcaed93cc91969bdee Mon Sep 17 00:00:00 2001
From: Ralph Goers <rgoers@apache.org>
Date: Mon, 29 Nov 2021 22:28:07 -0700
Subject: [PATCH] Restrict LDAP access via JNDI
---
log4j-core/pom.xml | 5 +
.../log4j/core/appender/mom/JmsAppender.java | 31 ++++-
.../logging/log4j/core/lookup/JndiLookup.java | 5 +
.../logging/log4j/core/net/JndiManager.java | 106 ++++++++++++++-
.../logging/log4j/core/util/NetUtils.java | 44 +++++++
.../log4j/core/lookup/JndiExploit.java | 36 +++++
.../log4j/core/lookup/JndiLdapLookupTest.java | 124 ++++++++++++++++++
.../src/test/resources/java-import.ldif | 4 +
pom.xml | 6 +
9 files changed, 353 insertions(+), 8 deletions(-)
create mode 100644 log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiExploit.java
create mode 100644 log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiLdapLookupTest.java
create mode 100644 log4j-core/src/test/resources/java-import.ldif
diff --git a/log4j-core/pom.xml b/log4j-core/pom.xml
index 5d24d6f..3afa014 100644
--- a/log4j-core/pom.xml
+++ b/log4j-core/pom.xml
@@ -332,6 +332,11 @@
<artifactId>HdrHistogram</artifactId>
<scope>test</scope>
</dependency>
+ <dependency>
+ <groupId>org.zapodot</groupId>
+ <artifactId>embedded-ldap-junit</artifactId>
+ <scope>test</scope>
+ </dependency>
</dependencies>
<build>
<plugins>
diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/mom/JmsAppender.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/mom/JmsAppender.java
index ddac666..f2190ca 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/mom/JmsAppender.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/mom/JmsAppender.java
@@ -88,6 +88,12 @@ public class JmsAppender extends AbstractAppender {
@PluginBuilderAttribute
private boolean immediateFail;
+ @PluginBuilderAttribute
+ private String allowedLdapClasses;
+
+ @PluginBuilderAttribute
+ private String allowedLdapHosts;
+
// Programmatic access only for now.
private JmsManager jmsManager;
@@ -100,8 +106,18 @@ public class JmsAppender extends AbstractAppender {
JmsManager actualJmsManager = jmsManager;
JmsManagerConfiguration configuration = null;
if (actualJmsManager == null) {
+ Properties additionalProperties = null;
+ if (allowedLdapClasses != null || allowedLdapHosts != null) {
+ additionalProperties = new Properties();
+ if (allowedLdapHosts != null) {
+ additionalProperties.put(JndiManager.ALLOWED_HOSTS, allowedLdapHosts);
+ }
+ if (allowedLdapClasses != null) {
+ additionalProperties.put(JndiManager.ALLOWED_CLASSES, allowedLdapClasses);
+ }
+ }
final Properties jndiProperties = JndiManager.createProperties(factoryName, providerUrl, urlPkgPrefixes,
- securityPrincipalName, securityCredentials, null);
+ securityPrincipalName, securityCredentials, additionalProperties);
configuration = new JmsManagerConfiguration(jndiProperties, factoryBindingName, destinationBindingName,
userName, password, false, reconnectIntervalMillis);
actualJmsManager = AbstractManager.getManager(getName(), JmsManager.FACTORY, configuration);
@@ -202,6 +218,16 @@ public class JmsAppender extends AbstractAppender {
return this;
}
+ public Builder setAllowedLdapClasses(final String allowedLdapClasses) {
+ this.allowedLdapClasses = allowedLdapClasses;
+ return this;
+ }
+
+ public Builder setAllowedLdapHosts(final String allowedLdapHosts) {
+ this.allowedLdapHosts = allowedLdapHosts;
+ return this;
+ }
+
/**
* Does not include the password.
*/
@@ -212,7 +238,8 @@ public class JmsAppender extends AbstractAppender {
+ ", securityCredentials=" + securityCredentials + ", factoryBindingName=" + factoryBindingName
+ ", destinationBindingName=" + destinationBindingName + ", username=" + userName + ", layout="
+ getLayout() + ", filter=" + getFilter() + ", ignoreExceptions=" + isIgnoreExceptions()
- + ", jmsManager=" + jmsManager + "]";
+ + ", jmsManager=" + jmsManager + ", allowedLdapClasses=" + allowedLdapClasses
+ + ", allowedLdapHosts=" + allowedLdapHosts + "]";
}
}
diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/lookup/JndiLookup.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/lookup/JndiLookup.java
index 30e65ad..e57d0be 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/lookup/JndiLookup.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/lookup/JndiLookup.java
@@ -16,6 +16,11 @@
*/
package org.apache.logging.log4j.core.lookup;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.List;
import java.util.Objects;
import javax.naming.NamingException;
diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/net/JndiManager.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/net/JndiManager.java
index 2670857..8a0e68d 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/net/JndiManager.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/net/JndiManager.java
@@ -17,31 +17,76 @@
package org.apache.logging.log4j.core.net;
+import java.io.Serializable;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
import java.util.Properties;
import java.util.concurrent.TimeUnit;
import javax.naming.Context;
-import javax.naming.InitialContext;
+import javax.naming.NameClassPair;
+import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
+import javax.naming.Referenceable;
+import javax.naming.directory.Attribute;
+import javax.naming.directory.Attributes;
+import javax.naming.directory.DirContext;
+import javax.naming.directory.InitialDirContext;
import org.apache.logging.log4j.core.appender.AbstractManager;
import org.apache.logging.log4j.core.appender.ManagerFactory;
import org.apache.logging.log4j.core.util.JndiCloser;
+import org.apache.logging.log4j.core.util.NetUtils;
+import org.apache.logging.log4j.util.PropertiesUtil;
/**
- * Manages a JNDI {@link javax.naming.Context}.
+ * Manages a JNDI {@link javax.naming.directory.DirContext}.
*
* @since 2.1
*/
public class JndiManager extends AbstractManager {
+ public static final String ALLOWED_HOSTS = "allowedLdapHosts";
+ public static final String ALLOWED_CLASSES = "allowedLdapClasses";
+
private static final JndiManagerFactory FACTORY = new JndiManagerFactory();
+ private static final String PREFIX = "log4j2.";
+ private static final List<String> permanentAllowedHosts = new ArrayList<>();
+ private static final List<String> permanentAllowedClasses = new ArrayList<>();
+ private static final String LDAP = "ldap";
+ private static final String SERIALIZED_DATA = "javaserializeddata";
+ private static final String CLASS_NAME = "javaclassname";
+ private static final String REFERENCE_ADDRESS = "javareferenceaddress";
+ private static final String OBJECT_FACTORY = "javafactory";
+ private final List<String> allowedHosts;
+ private final List<String> allowedClasses;
+
+ static {
+ permanentAllowedHosts.addAll(NetUtils.getLocalIps());
+ permanentAllowedClasses.add(Boolean.class.getName());
+ permanentAllowedClasses.add(Byte.class.getName());
+ permanentAllowedClasses.add(Character.class.getName());
+ permanentAllowedClasses.add(Double.class.getName());
+ permanentAllowedClasses.add(Float.class.getName());
+ permanentAllowedClasses.add(Integer.class.getName());
+ permanentAllowedClasses.add(Long.class.getName());
+ permanentAllowedClasses.add(Number.class.getName());
+ permanentAllowedClasses.add(Short.class.getName());
+ permanentAllowedClasses.add(String.class.getName());
+ }
- private final Context context;
- private JndiManager(final String name, final Context context) {
+ private final DirContext context;
+
+ private JndiManager(final String name, final DirContext context, final List<String> allowedHosts,
+ final List<String> allowedClasses) {
super(null, name);
this.context = context;
+ this.allowedHosts = allowedHosts;
+ this.allowedClasses = allowedClasses;
}
/**
@@ -168,7 +213,37 @@ public class JndiManager extends AbstractManager {
* @throws NamingException if a naming exception is encountered
*/
@SuppressWarnings("unchecked")
- public <T> T lookup(final String name) throws NamingException {
+ public synchronized <T> T lookup(final String name) throws NamingException {
+ try {
+ URI uri = new URI(name);
+ if (LDAP.equalsIgnoreCase(uri.getScheme())) {
+ if (!allowedHosts.contains(uri.getHost())) {
+ LOGGER.warn("Attempt to access ldap server not in allowed list");
+ return null;
+ }
+ Attributes attributes = this.context.getAttributes(name);
+ if (attributes != null) {
+ Attribute classNameAttr = attributes.get(CLASS_NAME);
+ if (attributes.get(SERIALIZED_DATA) != null) {
+ if (classNameAttr != null) {
+ String className = classNameAttr.get().toString();
+ if (!allowedClasses.contains(className)) {
+ LOGGER.warn("Deserialization of {} is not allowed", className);
+ return null;
+ }
+ } else {
+ LOGGER.warn("No class name provided for {}", name);
+ return null;
+ }
+ } else if (attributes.get(REFERENCE_ADDRESS) != null || attributes.get(OBJECT_FACTORY) != null){
+ LOGGER.warn("Referenceable class is not allowed for {}", name);
+ return null;
+ }
+ }
+ }
+ } catch (URISyntaxException ex) {
+ // This is OK.
+ }
return (T) this.context.lookup(name);
}
@@ -176,13 +251,32 @@ public class JndiManager extends AbstractManager {
@Override
public JndiManager createManager(final String name, final Properties data) {
+ String hosts = data != null ? data.getProperty(ALLOWED_HOSTS) : null;
+ String classes = data != null ? data.getProperty(ALLOWED_CLASSES) : null;
+ List<String> allowedHosts = new ArrayList<>();
+ List<String> allowedClasses = new ArrayList<>();
+ addAll(hosts, allowedHosts, permanentAllowedHosts, ALLOWED_HOSTS, data);
+ addAll(classes, allowedClasses, permanentAllowedClasses, ALLOWED_CLASSES, data);
try {
- return new JndiManager(name, new InitialContext(data));
+ return new JndiManager(name, new InitialDirContext(data), allowedHosts, allowedClasses);
} catch (final NamingException e) {
LOGGER.error("Error creating JNDI InitialContext.", e);
return null;
}
}
+
+ private void addAll(String toSplit, List<String> list, List<String> permanentList, String propertyName,
+ Properties data) {
+ if (toSplit != null) {
+ list.addAll(Arrays.asList(toSplit.split("\\s*,\\s*")));
+ data.remove(propertyName);
+ }
+ toSplit = PropertiesUtil.getProperties().getStringProperty(PREFIX + propertyName);
+ if (toSplit != null) {
+ list.addAll(Arrays.asList(toSplit.split("\\s*,\\s*")));
+ }
+ list.addAll(permanentList);
+ }
}
@Override
diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java
index e848822..b9a01ae 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java
@@ -17,6 +17,8 @@
package org.apache.logging.log4j.core.util;
import java.io.File;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.NetworkInterface;
@@ -25,11 +27,14 @@ import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.UnknownHostException;
+import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
+import java.util.List;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.status.StatusLogger;
+import org.apache.logging.log4j.util.Strings;
/**
* Networking-related convenience methods.
@@ -78,6 +83,45 @@ public final class NetUtils {
}
}
+ public static List<String> getLocalIps() {
+ List<String> localIps = new ArrayList<>();
+ localIps.add("localhost");
+ localIps.add("127.0.0.1");
+ try {
+ final InetAddress addr = Inet4Address.getLocalHost();
+ setHostName(addr, localIps);
+ } catch (final UnknownHostException ex) {
+ // Ignore this.
+ }
+ try {
+ final Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
+ if (interfaces != null) {
+ while (interfaces.hasMoreElements()) {
+ final NetworkInterface nic = interfaces.nextElement();
+ final Enumeration<InetAddress> addresses = nic.getInetAddresses();
+ while (addresses.hasMoreElements()) {
+ final InetAddress address = addresses.nextElement();
+ setHostName(address, localIps);
+ }
+ }
+ }
+ } catch (final SocketException se) {
+ // ignore.
+ }
+ return localIps;
+ }
+
+ private static void setHostName(InetAddress address, List<String> localIps) {
+ String[] parts = address.toString().split("\\s*/\\s*");
+ if (parts.length > 0) {
+ for (String part : parts) {
+ if (Strings.isNotBlank(part) && !localIps.contains(part)) {
+ localIps.add(part);
+ }
+ }
+ }
+ }
+
/**
* Returns the local network interface's MAC address if possible. The local network interface is defined here as
* the {@link java.net.NetworkInterface} that is both up and not a loopback interface.
diff --git a/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiExploit.java b/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiExploit.java
new file mode 100644
index 0000000..7b0ae46
--- /dev/null
+++ b/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiExploit.java
@@ -0,0 +1,36 @@
+/*
+ * 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.logging.log4j.core.lookup;
+
+import javax.naming.Context;
+import javax.naming.Name;
+import javax.naming.spi.ObjectFactory;
+import java.util.Hashtable;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+/**
+ * Test LDAP object
+ */
+public class JndiExploit implements ObjectFactory {
+ @Override
+ public Object getObjectInstance(Object obj, Name name, Context nameCtx, Hashtable<?, ?> environment)
+ throws Exception {
+ fail("getObjectInstance must not be allowed");
+ return null;
+ }
+}
diff --git a/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiLdapLookupTest.java b/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiLdapLookupTest.java
new file mode 100644
index 0000000..73129f5
--- /dev/null
+++ b/log4j-core/src/test/java/org/apache/logging/log4j/core/lookup/JndiLdapLookupTest.java
@@ -0,0 +1,124 @@
+/*
+ * 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.logging.log4j.core.lookup;
+
+import javax.naming.Context;
+import javax.naming.NamingException;
+import javax.naming.Reference;
+import javax.naming.Referenceable;
+import javax.naming.StringRefAddr;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.message.SimpleMessage;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.zapodot.junit.ldap.EmbeddedLdapRule;
+import org.zapodot.junit.ldap.EmbeddedLdapRuleBuilder;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+/**
+ * JndiLookupTest
+ */
+public class JndiLdapLookupTest {
+
+ private static final String LDAP_URL = "ldap://127.0.0.1:";
+ private static final String RESOURCE = "JndiExploit";
+ private static final String TEST_STRING = "TestString";
+ private static final String TEST_MESSAGE = "TestMessage";
+ private static final String LEVEL = "TestLevel";
+ public static final String DOMAIN_DSN = "dc=apache,dc=org";
+
+ @Rule
+ public EmbeddedLdapRule embeddedLdapRule = EmbeddedLdapRuleBuilder.newInstance().usingDomainDsn(DOMAIN_DSN)
+ .importingLdifs("java-import.ldif").build();
+
+ @BeforeClass
+ public static void beforeClass() {
+ System.setProperty("log4j2.allowedLdapClasses", Level.class.getName());
+ }
+
+ @Test
+ public void testReferenceLookup() throws Exception {
+ int port = embeddedLdapRule.embeddedServerPort();
+ Context context = embeddedLdapRule.context();
+ context.bind( "cn=" + RESOURCE +"," + DOMAIN_DSN, new Fruit("Test Message"));
+ final StrLookup lookup = new JndiLookup();
+ String result = lookup.lookup(LDAP_URL + port + "/" + "cn=" + RESOURCE + "," + DOMAIN_DSN);
+ if (result != null) {
+ fail("Lookup returned an object");
+ }
+ }
+
+ @Test
+ public void testSerializableLookup() throws Exception {
+ int port = embeddedLdapRule.embeddedServerPort();
+ Context context = embeddedLdapRule.context();
+ context.bind( "cn=" + TEST_STRING +"," + DOMAIN_DSN, "Test Message");
+ final StrLookup lookup = new JndiLookup();
+ String result = lookup.lookup(LDAP_URL + port + "/" + "cn=" + TEST_STRING + "," + DOMAIN_DSN);
+ if (result == null) {
+ fail("Lookup failed to return the test string");
+ }
+ assertEquals("Incorrect message returned", "Test Message", result);
+ }
+
+ @Test
+ public void testBadSerializableLookup() throws Exception {
+ int port = embeddedLdapRule.embeddedServerPort();
+ Context context = embeddedLdapRule.context();
+ context.bind( "cn=" + TEST_MESSAGE +"," + DOMAIN_DSN, new SimpleMessage("Test Message"));
+ final StrLookup lookup = new JndiLookup();
+ String result = lookup.lookup(LDAP_URL + port + "/" + "cn=" + TEST_MESSAGE + "," + DOMAIN_DSN);
+ if (result != null) {
+ fail("Lookup returned an object");
+ }
+ }
+
+ @Test
+ public void testSpecialSerializableLookup() throws Exception {
+ int port = embeddedLdapRule.embeddedServerPort();
+ Context context = embeddedLdapRule.context();
+ context.bind( "cn=" + LEVEL +"," + DOMAIN_DSN, Level.ERROR);
+ final StrLookup lookup = new JndiLookup();
+ String result = lookup.lookup(LDAP_URL + port + "/" + "cn=" + LEVEL + "," + DOMAIN_DSN);
+ if (result == null) {
+ fail("Lookup failed to return the level");
+ }
+ assertEquals("Incorrect level returned", Level.ERROR.toString(), result);
+ }
+
+ class Fruit implements Referenceable {
+ String fruit;
+ public Fruit(String f) {
+ fruit = f;
+ }
+
+ public Reference getReference() throws NamingException {
+
+ return new Reference(Fruit.class.getName(), new StringRefAddr("fruit",
+ fruit), JndiExploit.class.getName(), null); // factory location
+ }
+
+ public String toString() {
+ return fruit;
+ }
+ }
+
+}
diff --git a/log4j-core/src/test/resources/java-import.ldif b/log4j-core/src/test/resources/java-import.ldif
new file mode 100644
index 0000000..35daf43
--- /dev/null
+++ b/log4j-core/src/test/resources/java-import.ldif
@@ -0,0 +1,4 @@
+dn: dc=apache,dc=org
+objectClass: domain
+objectClass: top
+dc: apache
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index d74175d..6fd99f1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -868,6 +868,12 @@
<version>2.2.0</version>
<scope>test</scope>
</dependency>
+ <!-- Testing LDAP -->
+ <dependency>
+ <groupId>org.zapodot</groupId>
+ <artifactId>embedded-ldap-junit</artifactId>
+ <version>0.8.1</version>
+ </dependency>
</dependencies>
</dependencyManagement>
<build>
--
2.27.0
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