ground418 security advisory Date: 28-11-2006 Subject: Multiple Vulnerabilities in AlternC version 0.9.5 (and below). Author: Vincent Audet Mnard <thabob (at) gmail (dot) com [email concealed]> Original File: http://www.ground418.org/exploits/read.php?file=06-alternC-095.txt Related Files: http://dev.alternc.org/trac/alternc/changeset/1737 http://dev.alternc.org/trac/alternc/changeset/1738 http://dev.alternc.org/trac/alternc/changeset/1739 Vendor: http://www.alternc.org/ Vulnerabilities: - Possible XSS - Remote code execution - Unauthorized file and folder creation - Full file system reading access Risk: high -[ 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 ] It is possible to execute javascript by creating a directory with the 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 warnings. 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 critical flaws. 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 https://dev.alternc.org/trac/alternc/milestone/0.9.6 Vincent A. Menard