1. OVERVIEW SilverStripe 2.4.7 and lower versions are vulnerable to Open URL Redirection. 2. BACKGROUND SilverStripe CMS is easy for both developers and content authors to work with. The SilverStripe Framework keeps the code tucked away neatly so that it can be accessed easily by programmers but does not get in the way of content authors. 3. VULNERABILITY DESCRIPTION SilverStripe CMS contains a flaw that allows a remote cross site redirection attack. This flaw exists because the application does not validate the "BackURL" parameter upon submission to the "/index.php/Security/login" script. This could allow a user to create a specially crafted URL, that if clicked, would redirect a victim from the intended legitimate web site to an arbitrary web site of the attacker's choosing. 4. VERSIONS AFFECTED Tested on 2.4.7 5. PROOF-OF-CONCEPT/EXPLOIT http://localhost/index.php/Security/login?BackURL=//yehg.net 6. SOLUTION Upgrade to the latest 3.x version. 7. VENDOR SilverStripe Development Team http://www.silverstripe.org/ 8. CREDIT This vulnerability was discovered by Aung Khant, http://yehg.net, YGN Ethical Hacker Group, Myanmar. 9. DISCLOSURE TIME-LINE 2012-02-06: notified vendor 2012-10-15: vulnerability disclosed 10. REFERENCES Original Advisory URL: http://yehg.net/lab/pr0js/advisories/%5BSilverStripe_2.4.7%5D_url_redirection #yehg [2012-10-15]