From bb095154be011267b64e37a1d401546e7cc2b7c3 Mon Sep 17 00:00:00 2001
From: Ceki Gulcu <ceki@qos.ch>
Date: Fri, 1 Dec 2023 15:12:22 +0100
Subject: [PATCH] fix CVE-2023-6378

Signed-off-by: Ceki Gulcu <ceki@qos.ch>
---
 .../logback/classic/spi/LoggingEventVO.java   |  7 ++
 .../src/test/input/issue/logback-1754.xml     | 30 +++++++
 .../issue/logback_1754/LogbackTest.java       | 78 +++++++++++++++++++
 .../core/net/HardenedObjectInputStream.java   | 55 ++++++++++++-
 .../ch/qos/logback/core/util/EnvUtil.java     | 39 ++++++----
 .../net/HardenedObjectInputStreamTest.java    | 49 +++++++++++-
 .../rolling/ScaffoldingForRollingTests.java   |  2 +-
 .../ch/qos/logback/core/util/EnvUtilTest.java | 34 ++++++++
 8 files changed, 275 insertions(+), 19 deletions(-)
 create mode 100644 logback-classic/src/test/input/issue/logback-1754.xml
 create mode 100644 logback-classic/src/test/java/ch/qos/logback/classic/issue/logback_1754/LogbackTest.java
 create mode 100644 logback-core/src/test/java/ch/qos/logback/core/util/EnvUtilTest.java

diff --git a/logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggingEventVO.java b/logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggingEventVO.java
index e21350b2cc..ea2c6ac128 100644
--- a/logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggingEventVO.java
+++ b/logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggingEventVO.java
@@ -14,6 +14,7 @@
 package ch.qos.logback.classic.spi;
 
 import java.io.IOException;
+import java.io.InvalidObjectException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
@@ -38,6 +39,7 @@ public class LoggingEventVO implements ILoggingEvent, Serializable {
 
     private static final int NULL_ARGUMENT_ARRAY = -1;
     private static final String NULL_ARGUMENT_ARRAY_ELEMENT = "NULL_ARGUMENT_ARRAY_ELEMENT";
+    private static final int ARGUMENT_ARRAY_DESERIALIZATION_LIMIT = 128;
 
     private String threadName;
     private String loggerName;
@@ -181,6 +183,11 @@ private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundE
         level = Level.toLevel(levelInt);
 
         int argArrayLen = in.readInt();
+        // Prevent DOS attacks via large or negative arrays
+        if (argArrayLen < NULL_ARGUMENT_ARRAY || argArrayLen > ARGUMENT_ARRAY_DESERIALIZATION_LIMIT) {
+            throw new InvalidObjectException("Argument array length is invalid: " + argArrayLen);
+        }
+
         if (argArrayLen != NULL_ARGUMENT_ARRAY) {
             argumentArray = new String[argArrayLen];
             for (int i = 0; i < argArrayLen; i++) {
diff --git a/logback-classic/src/test/input/issue/logback-1754.xml b/logback-classic/src/test/input/issue/logback-1754.xml
new file mode 100644
index 0000000000..ab41185a34
--- /dev/null
+++ b/logback-classic/src/test/input/issue/logback-1754.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Logback: the reliable, generic, fast and flexible logging framework.
+  ~ Copyright (C) 1999-2023, QOS.ch. All rights reserved.
+  ~
+  ~ This program and the accompanying materials are dual-licensed under
+  ~ either the terms of the Eclipse Public License v1.0 as published by
+  ~ the Eclipse Foundation
+  ~
+  ~   or (per the licensee's choosing)
+  ~
+  ~ under the terms of the GNU Lesser General Public License version 2.1
+  ~ as published by the Free Software Foundation.
+  -->
+
+<configuration debug="true">
+    <appender name="GENERAL" class="ch.qos.logback.core.rolling.RollingFileAppender">
+        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
+            <fileNamePattern>${logback_1754_targetDirectory}/test-%d{yyyy-MM-dd}.log</fileNamePattern>
+            <maxHistory>120</maxHistory>
+        </rollingPolicy>
+        <encoder>
+            <pattern>%date{HH:mm:ss.SSS} [%level] %logger{0} [%thread] [%class{3}:%line] : %msg%n</pattern>
+        </encoder>
+        <prudent>true</prudent>
+    </appender>
+    <root level="debug">
+        <appender-ref ref="GENERAL" />
+    </root>
+</configuration>
\ No newline at end of file
diff --git a/logback-classic/src/test/java/ch/qos/logback/classic/issue/logback_1754/LogbackTest.java b/logback-classic/src/test/java/ch/qos/logback/classic/issue/logback_1754/LogbackTest.java
new file mode 100644
index 0000000000..3001c00a66
--- /dev/null
+++ b/logback-classic/src/test/java/ch/qos/logback/classic/issue/logback_1754/LogbackTest.java
@@ -0,0 +1,78 @@
+/*
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2023, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+
+package ch.qos.logback.classic.issue.logback_1754;
+
+import ch.qos.logback.classic.ClassicConstants;
+import ch.qos.logback.classic.ClassicTestConstants;
+import ch.qos.logback.core.testUtil.RandomUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+
+import static ch.qos.logback.classic.util.ContextInitializer.CONFIG_FILE_PROPERTY;
+
+public class LogbackTest {
+
+    private static final int THREADS = 16;
+
+    private void runTest() {
+
+        int diff = RandomUtil.getPositiveInt();
+        //System.setProperty("logback.statusListenerClass", "sysout");
+        System.setProperty(CONFIG_FILE_PROPERTY, ClassicTestConstants.INPUT_PREFIX+"issue/logback-1754.xml");
+        System.setProperty("logback_1754_targetDirectory", ClassicTestConstants.OUTPUT_DIR_PREFIX+"safeWrite_"+diff);
+
+        CountDownLatch latch = new CountDownLatch(THREADS);
+        List<Thread> threads = new ArrayList<Thread>(THREADS);
+        for (int i = 0; i < THREADS; i++) {
+            LoggerThread thread = new LoggerThread(latch, "message from thread " + i);
+            thread.start();
+            threads.add(thread);
+        }
+        for (Thread thread : threads) {
+            try {
+                thread.join();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public static void main(String... args) {
+        new LogbackTest().runTest();
+    }
+
+    private static final class LoggerThread extends Thread {
+        private static final Logger LOG = LoggerFactory.getLogger(LoggerThread.class);
+        private final CountDownLatch latch;
+        private final String message;
+
+        LoggerThread(CountDownLatch latch, String message) {
+            setDaemon(false);
+            this.latch = latch;
+            this.message = message;
+        }
+
+        @Override
+        public void run() {
+            latch.countDown();
+            LOG.info(message);
+        }
+    }
+}
diff --git a/logback-core/src/main/java/ch/qos/logback/core/net/HardenedObjectInputStream.java b/logback-core/src/main/java/ch/qos/logback/core/net/HardenedObjectInputStream.java
index d1b7301ea4..0674aaf3ea 100755
--- a/logback-core/src/main/java/ch/qos/logback/core/net/HardenedObjectInputStream.java
+++ b/logback-core/src/main/java/ch/qos/logback/core/net/HardenedObjectInputStream.java
@@ -1,10 +1,27 @@
+/**
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2023, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
 package ch.qos.logback.core.net;
 
+import ch.qos.logback.core.util.EnvUtil;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InvalidClassException;
 import java.io.ObjectInputStream;
 import java.io.ObjectStreamClass;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -22,10 +39,12 @@ public class HardenedObjectInputStream extends ObjectInputStream {
 
     final List<String> whitelistedClassNames;
     final static String[] JAVA_PACKAGES = new String[] { "java.lang", "java.util" };
+    final private static int DEPTH_LIMIT = 16;
+    final private static int ARRAY_LIMIT = 10000;
 
     public HardenedObjectInputStream(InputStream in, String[] whilelist) throws IOException {
         super(in);
-
+        initObjectFilter();
         this.whitelistedClassNames = new ArrayList<String>();
         if (whilelist != null) {
             for (int i = 0; i < whilelist.length; i++) {
@@ -36,11 +55,43 @@ public HardenedObjectInputStream(InputStream in, String[] whilelist) throws IOEx
 
     public HardenedObjectInputStream(InputStream in, List<String> whitelist) throws IOException {
         super(in);
-
+        initObjectFilter();
         this.whitelistedClassNames = new ArrayList<String>();
         this.whitelistedClassNames.addAll(whitelist);
     }
 
+    private void initObjectFilter() {
+
+        // invoke the following code by reflection
+        //  this.setObjectInputFilter(ObjectInputFilter.Config.createFilter(
+        //                "maxarray=" + ARRAY_LIMIT + ";maxdepth=" + DEPTH_LIMIT + ";"
+        //        ));
+        if(EnvUtil.isJDK9OrHigher()) {
+            try {
+                ClassLoader classLoader = this.getClass().getClassLoader();
+
+                Class oifClass = classLoader.loadClass("java.io.ObjectInputFilter");
+                Class oifConfigClass = classLoader.loadClass("java.io.ObjectInputFilter$Config");
+                Method setObjectInputFilterMethod = this.getClass().getMethod("setObjectInputFilter", oifClass);
+
+                Method createFilterMethod = oifConfigClass.getMethod("createFilter", String.class);
+                Object filter = createFilterMethod.invoke(null, "maxarray=" + ARRAY_LIMIT + ";maxdepth=" + DEPTH_LIMIT + ";");
+                setObjectInputFilterMethod.invoke(this, filter);
+            } catch (ClassNotFoundException e) {
+                // this code should be unreachable
+                throw new RuntimeException("Failed to initialize object filter", e);
+            } catch (InvocationTargetException e) {
+                // this code should be unreachable
+                throw new RuntimeException("Failed to initialize object filter", e);
+            } catch (NoSuchMethodException e) {
+                // this code should be unreachable
+                throw new RuntimeException("Failed to initialize object filter", e);
+            } catch (IllegalAccessException e) {
+                // this code should be unreachable
+                throw new RuntimeException("Failed to initialize object filter", e);
+            }
+        }
+    }
     @Override
     protected Class<?> resolveClass(ObjectStreamClass anObjectStreamClass) throws IOException, ClassNotFoundException {
         
diff --git a/logback-core/src/main/java/ch/qos/logback/core/util/EnvUtil.java b/logback-core/src/main/java/ch/qos/logback/core/util/EnvUtil.java
index c200a1c984..f3dcd0cfe3 100644
--- a/logback-core/src/main/java/ch/qos/logback/core/util/EnvUtil.java
+++ b/logback-core/src/main/java/ch/qos/logback/core/util/EnvUtil.java
@@ -1,6 +1,6 @@
 /**
  * Logback: the reliable, generic, fast and flexible logging framework.
- * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
+ * Copyright (C) 1999-2023, QOS.ch. All rights reserved.
  *
  * This program and the accompanying materials are dual-licensed under
  * either the terms of the Eclipse Public License v1.0 as published by
@@ -22,22 +22,27 @@
 public class EnvUtil {
 
     static private boolean isJDK_N_OrHigher(int n) {
-        List<String> versionList = new ArrayList<String>();
-        // this code should work at least until JDK 10 (assuming n parameter is
-        // always 6 or more)
-        for (int i = 0; i < 5; i++) {
-            versionList.add("1." + (n + i));
-        }
-
-        String javaVersion = System.getProperty("java.version");
-        if (javaVersion == null) {
+        String javaVersionStr = System.getProperty("java.version", "");
+        if (javaVersionStr.isEmpty())
             return false;
+
+        int version = getJDKVersion(javaVersionStr);
+        return version > 0 && n <= version;
+    }
+
+    static public int getJDKVersion(String javaVersionStr) {
+        int version = 0;
+
+        for (char ch : javaVersionStr.toCharArray()) {
+            if (Character.isDigit(ch)) {
+                version = (version * 10) + (ch - 48);
+            } else if (version == 1) {
+                version = 0;
+            } else {
+                break;
+            }
         }
-        for (String v : versionList) {
-            if (javaVersion.startsWith(v))
-                return true;
-        }
-        return false;
+        return version;
     }
 
     static public boolean isJDK5() {
@@ -52,6 +57,10 @@ static public boolean isJDK7OrHigher() {
         return isJDK_N_OrHigher(7);
     }
 
+    static public boolean isJDK9OrHigher() {
+        return isJDK_N_OrHigher(9);
+    }
+
     static public boolean isJaninoAvailable() {
         ClassLoader classLoader = EnvUtil.class.getClassLoader();
         try {
diff --git a/logback-core/src/test/java/ch/qos/logback/core/net/HardenedObjectInputStreamTest.java b/logback-core/src/test/java/ch/qos/logback/core/net/HardenedObjectInputStreamTest.java
index ff4ddc599f..36f7f11b59 100755
--- a/logback-core/src/test/java/ch/qos/logback/core/net/HardenedObjectInputStreamTest.java
+++ b/logback-core/src/test/java/ch/qos/logback/core/net/HardenedObjectInputStreamTest.java
@@ -1,12 +1,17 @@
 package ch.qos.logback.core.net;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InvalidClassException;
 import java.io.ObjectOutputStream;
+import java.util.HashSet;
+import java.util.Set;
 
+import ch.qos.logback.core.util.EnvUtil;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -54,5 +59,47 @@ private void writeObject(ObjectOutputStream oos, Object o) throws IOException {
         oos.flush();
         oos.close();
     }
-    
+
+    @Test
+    public void denialOfService() throws ClassNotFoundException, IOException {
+
+        if(!EnvUtil.isJDK9OrHigher()) {
+            return;
+        }
+
+        ByteArrayInputStream bis = new ByteArrayInputStream(payload());
+        inputStream = new HardenedObjectInputStream(bis, whitelist);
+        try {
+            inputStream.readObject();
+            fail("InvalidClassException expected");
+        } catch(InvalidClassException e) {
+        }
+        finally {
+            inputStream.close();
+        }
+    }
+
+    private byte[] payload() throws IOException {
+        Set root = buildEvilHashset();
+        writeObject(oos, root);
+        return bos.toByteArray();
+    }
+
+    private Set buildEvilHashset() {
+        Set root = new HashSet();
+        Set s1 = root;
+        Set s2 = new HashSet();
+        for (int i = 0; i < 100; i++) {
+            Set t1 = new HashSet();
+            Set t2 = new HashSet();
+            t1.add("foo"); // make it not equal to t2
+            s1.add(t1);
+            s1.add(t2);
+            s2.add(t1);
+            s2.add(t2);
+            s1 = t1;
+            s2 = t2;
+        }
+        return root;
+    }
 }
diff --git a/logback-core/src/test/java/ch/qos/logback/core/rolling/ScaffoldingForRollingTests.java b/logback-core/src/test/java/ch/qos/logback/core/rolling/ScaffoldingForRollingTests.java
index 57389be3f7..504b52adc2 100755
--- a/logback-core/src/test/java/ch/qos/logback/core/rolling/ScaffoldingForRollingTests.java
+++ b/logback-core/src/test/java/ch/qos/logback/core/rolling/ScaffoldingForRollingTests.java
@@ -24,10 +24,10 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.sql.Date;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Calendar;
+import java.util.Date;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.concurrent.Future;
diff --git a/logback-core/src/test/java/ch/qos/logback/core/util/EnvUtilTest.java b/logback-core/src/test/java/ch/qos/logback/core/util/EnvUtilTest.java
new file mode 100644
index 0000000000..2ee4abd42e
--- /dev/null
+++ b/logback-core/src/test/java/ch/qos/logback/core/util/EnvUtilTest.java
@@ -0,0 +1,34 @@
+/**
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2023, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+package ch.qos.logback.core.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class EnvUtilTest {
+
+
+    @Test
+    public void jdkVersion() {
+        assertEquals(4, EnvUtil.getJDKVersion("1.4.xx"));
+        assertEquals(5, EnvUtil.getJDKVersion("1.5"));
+        assertEquals(5, EnvUtil.getJDKVersion("1.5.xx"));
+        assertEquals(5, EnvUtil.getJDKVersion("1.5AA"));
+        assertEquals(9, EnvUtil.getJDKVersion("9EA"));
+        assertEquals(9, EnvUtil.getJDKVersion("9.0.1"));
+        assertEquals(18, EnvUtil.getJDKVersion("18.3+xx"));
+        assertEquals(21, EnvUtil.getJDKVersion("21.0.1"));
+    }
+}
