[MajorSecurity SA-081]Contao CMS 2.9.2 - Persistent Cross Site Scripting Issue Details ============= Product: Contao CMS 2.9.2 Security-Risk: moderated Remote-Exploit: yes Vendor-URL: http://www.contao.org/ Advisory-Status: published Credits ============= Discovered by: David Vieira-Kurz of MajorSecurity Affected Products: ============= Contao CMS 2.9.2 Prior versions may also be vulnerable Description ============= "Contao is an open source content management system (CMS) for people who want a professional internet presence that is easy to maintain." - from www.contao.org More Details ============= I have discovered some vulnerabilities in Contao CMS 2.9.2, which can be exploited by malicious people to conduct persistent cross-site scripting attacks. Input passed directly over the "HTTP_X_FORWARDED_FOR" header in "/system/libraries/Environment.php" is not properly sanitised before being stored and returned to the user out from the "/system/modules/comments/Comments.php" file when the user browses the "/contao/main.php?do=comments" site. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site. Solution ============= Update to the patched version 2.9.3. Timeline ================ 2010-12-24, vendor informed ( see ticket 2751 ) 2011-01-01, vendor confirmed the issue 2011-01-06, vendor relased a patched version(2.9.3) 2011-01-12, advisory published Use of terms ================ Unaltered electronic reproduction of this advisory is permitted. For all other reproduction or publication, in printing or otherwise, contact us for permission. Use of the advisory constitutes acceptance for use in an "as is" condition. All warranties are excluded. In no event shall MajorSecurity be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if MajorSecurity has been advised of the possibility of such damages.