On the Content Security Policy Violations due to the Same-Origin Policy
Abstract
Modern browsers implement different security policies such as the Content Security Policy (CSP), a mechanism designed to mitigate popular web vulnerabilities, and the Same Origin Policy (SOP), a mechanism that governs interactions between resources of web pages. In this work, we describe how CSP may be violated due to the SOP when a page contains an embedded iframe from the same origin. We analyse 1 million pages from 10,000 top Alexa sites and report that at least 31.1% of current CSP-enabled pages are potentially vulnerable to CSP violations. Further considering real-world situations where those pages are involved in same-origin nested browsing contexts, we found that in at least 23.5% of the cases, CSP violations are possible. During our study, we also identified a divergence among browsers implementations in the enforcement of CSP in srcdoc sandboxed iframes, which actually reveals a problem in Gecko-based browsers CSP implementation. To ameliorate the problematic conflicts of the security mechanisms, we discuss measures to avoid CSP violations.
Keywords
Cite
@article{arxiv.1611.02875,
title = {On the Content Security Policy Violations due to the Same-Origin Policy},
author = {Dolière Francis Somé and Nataliia Bielova and Tamara Rezk},
journal= {arXiv preprint arXiv:1611.02875},
year = {2017}
}
Comments
8 pages + references for the short version, extended to 19 pages for detailed appendices