ground418 security advisory
Subject: Multiple Vulnerabilities in AlternC version 0.9.5 (and below).
Author: Vincent Audet Mnard <thabob (at) gmail (dot) com [email concealed]>
- Possible XSS
- Remote code execution
- Unauthorized file and folder creation
- Full file system reading access
-[ About alternC ]
AlternC is a open source hosting services software suite. AlternC
includes an automatic installation and configuration system, and a
web-based control panel to manage users' accounts and web services
(e.g. domains, emails, ftp accounts, statistics...).
-[ Remote code execution ]
file manager of AlternC.
Simply create a folder called
"<script>alert(document.cookie);</script>" to have a demonstration.
This could also lead to a path disclosure if php is set to show
Once the users used the phpmyadmin in alternC, the SQL password can be
seen (in plain text) in the cookie. This could lead to a SQL password
steal if used with a XSS.
-[ Unauthorized folder and file creation ]
You can create folders and files pretty much anywhere the alternC have
the right to do so simply by entering a filename like "../../test" in
the "create name" input.
-[ Full FileSystem reading access ]
When configuring a subdomain, you can indicate that the files will be
locally managed in a specific folder. You can configure your subdomain
to have the web root in "../../../../../" so that you
have complete access in reading (with the apache/alternC user
restriction) to the file system.
-[ Solution ]
Except for the SQL password visible in plain text, all these flaws are
because of a bad inputs sanitazation. Double dots and slashes should
not be permitted anywhere. The form's input in ('admin/bro_main.php',
'admin/dom_subedit.php', 'admin/dom_add.php') were causing the most
AlternC developers have been alerted few days ago and they released a
new version. We highly recommend you to stop using 0.9.5 and consider
upgrading to the newest version.
Version 0.9.6 is available at
Vincent A. Menard