Protecting browsers from cross-origin CSS attacks

Cross-origin CSS attacks use style sheet import to steal confidential information from a victim website, hijacking a user's existing authenticated session; existing XSS defenses are ineffective. We show how to conduct these attacks with any browser, even if JavaScript is disabled, and propose a client-side defense with little or no impact on the vast majority of web sites. We have implemented and deployed defenses in Firefox, Google Chrome, and Safari. Our defense proposal has also been adopted by Opera. Categories and Subject Descriptors K.6.5 [Management of Computing and Information Systems]: Security and Protection General Terms Security Keywords CSS, Content Type, Same-Origin Policy

• Type: Conference
• Year: 2010
• Where: CCS
• Authors: Lin-Shung Huang, Zack Weinberg, Chris Evans, Collin Jackson
• Keywords: CCS 2010, Cross-origin CSS, Security Privacy, Style Sheet Import, XSS Defenses