php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Bug #73630 Buildin-server - Overwrite $_SERVER['request_uri']
Submitted: 2016-11-30 22:24 UTC Modified: 2016-11-30 23:20 UTC
From: rskansing at gmail dot com Assigned:
Status: Open Package: Built-in web server
PHP Version: Irrelevant OS: Ubuntu 16.04
Private report: No CVE-ID: None
Have you experienced this issue?
Rate the importance of this bug to you:

 [2016-11-30 22:24 UTC] rskansing at gmail dot com
Description:
------------
It is possible to overwrite the contents of $_REQUEST_URI with a uri longer than 16400 bytes. It allows a attacker to manipulate the global variable in unexpected ways. It has low impact as it only related to the build in server.

Test script:
---------------
Create a file named testtest1.php with the following content
<a href="<?= $_SERVER['REQUEST_URI'] ?>">Unexpected url</a>

Start the buildin php server 
php -S localhost:8090

Go to the browser and execute the following script in the console
window.location.href = (url ='http://testtest1.php:8090/overflow.php?')+("x".repeat(16400-url.length)+"//example.com");

it changes the url to "http://testtest1:8090/overflow.php?[16365 x here][payload]

Expected result:
----------------
localhost:8090 + a long string

Actual result:
--------------
example.com 

Patches

Add a Patch

Pull Requests

Add a Pull Request

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2016-11-30 22:26 UTC] rskansing at gmail dot com
* testtest1.php should have been overflow.php
 [2016-11-30 23:19 UTC] stas@php.net
-Type: Security +Type: Bug
 [2016-11-30 23:20 UTC] stas@php.net
Built-in server is not a production facility.
 
PHP Copyright © 2001-2018 The PHP Group
All rights reserved.
Last updated: Mon Sep 24 17:01:25 2018 UTC