. . . ._ | _. .|_ _. _.;_/ [_)|(_]\_|[ )(_](_.| \.net | ._| "YA Book 0.98-alpha - Persistent XSS Vulnerability" by Omni 1) Infos --------- Date : 2007-04-23 Product : YA Book Version : 0.98-alpha - Prior version maybe also be affected Vendor : http://sourceforge.net/projects/yabook - http://www.phpee.com/ Vendor Status : 2007-04-23 -> Not Informed! 2007-04-24 -> Informed! Description : YaBook- Ya Book! ...or yet another guestbook. YaBook is a simple but powerful guestbook running on PHP 5. It features easy installation and customization, multi-language support, and an administration interface. Various database systems are supported. Google Dork : Powered by YaBook 0.98-alpha - "Powered by YaBook 0.98-alpha" Source : omnipresent - omni E-mail : omnipresent[at]email[dot]it - omni[at]playhack[dot]net Team : Playhack.net Security 2) Security Issues ------------------- --- [ Remote Persistent XSS ] --- ================================= YA Book is vulnerable to an XSS. A malicous user can put in the City Field HTML or JS code (in sigin module: http://host/path/index.php?mode=sign) as shown below: Eg script: <script>alert("XSS")</script> The vulnerability exist because the city field is not properly sanitized before being used! --- [ PoC ] --- =============== A guest can posts a new message and after put the right captcha :D he can puts in the city field a code like: <script>location.href="http://host.com"</script> for a redirect with JS or.. he can injects other (eg: HTML, JS) codes.. 3) Patch -------- Edit the source code to ensure that the input is properly sanitized before being used.