1. OVERVIEW F5 FirePass SSL VPN is vulnerable to Open URL Redirection. 2. BACKGROUND F5 FirePass SSL VPN provides secure remote access to enterprise applications and data for users over any device or network while protecting your corporate. (See http://www.f5.com/pdf/products/firepass-overview.pdf) 3. VULNERABILITY DESCRIPTION F5 FirePass SSL VPN contains a flaw that allows a remote cross site redirection attack. This flaw exists because the application does not validate the "refreshURL" parameter upon submission to the "my.activation.cns.php3" 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 4xxx Series 5. PROOF-OF-CONCEPT/EXPLOIT https://[VPN_HOST]/my.activation.cns.php3?langchar=&ui_translation=&refreshURL=http://yehg.net/ 6. SOLUTION We have not been informed of the fix. We believe this issue should be fixed by the time of releasing our advisory. 7. VENDOR F5 Networks, Inc. 8. CREDIT This vulnerability was discovered by Aung Khant, http://yehg.net, YGN Ethical Hacker Group, Myanmar. 9. DISCLOSURE TIME-LINE 2012-03-31: notified vendor 2012-04-04: vendor acknowledged 2012-10-20: vulnerability disclosed 10. REFERENCES Original Advisory URL: http://yehg.net/lab/pr0js/advisories/%5BF5_firepass4x%5D_url_redirection OWASP Top 10 2010 - A 10: http://www.owasp.org/index.php/Top_10_2010-A10-Unvalidated_Redirects_and_Forwards SANS Top 25 - Rank 23: http://cwe.mitre.org/top25/#CWE-601 CWE-601: http://cwe.mitre.org/data/definitions/601.html #yehg [2012-10-20]