Biblio

We present research on the security of the most popular websites, ranked according to Alexa's top one million list, based on an HTTP response headers analysis. For each of the domains included in the list, we made four different requests: an HTTP/1.1 request to the domain itself and to its "www" subdomain and two more equivalent HTTPS requests. Redirections were always followed. A detailed discussion of the request process and main outcomes is presented, including X.509 certificate issues and comparison of results with equivalent HTTP/2 requests. The body of the responses was discarded, and the HTTP response header fields were stored in a database. We analysed the prevalence of the most important response headers related to web security aspects. In particular, we took into account Strict- Transport-Security, Content-Security-Policy, X-XSS-Protection, X-Frame-Options, Set-Cookie (for session cookies) and X-Content-Type. We also reviewed the contents of response HTTP headers that potentially could reveal unwanted information, like Server (and related headers), Date and Referrer-Policy. This research offers an up-to-date survey of current prevalence of web security policies implemented through HTTP response headers and concludes that most popular sites tend to implement it noticeably more often than less popular ones. Equally, HTTPS sites seem to be far more eager to implement those policies than HTTP only websites. A comparison with previous works show that web security policies based on HTTP response headers are continuously growing, but still far from satisfactory widespread adoption.

The Web ecosystem has been evolving over the past years and new Internet protocols, namely HTTP/2 over TLS/TCP and QUIC/UDP, are now used to deliver Web contents. Similarly, CDNs (Content Delivery Network) are deployed worldwide, caching contents close to end-users to optimize web browsing quality. We present in this paper an analysis of the influence of the Internet protocols and CDN on the Top 10,000 Alexa websites, based on a 12-month measurement campaign (from April 2018 to April 2019) performed via our tool Web View [1]. Part of our measurements are made public, represented on a monitoring website1, showing the results for the Top 50 Alexa Websites plus few specific websites and 8 french websites, suggested by the French Agency in charge of regulating telecommunications. Our analysis of this long-term measurement campaign allows to better analyze the delivery of public websites. For instance, it shows that even if some argue that QUIC optimizes the quality, it is not observed in the real-life since QUIC is not largely deployed. Our method for analyzing CDN delivery in the Web browsing allows us to evaluate its influence, which is important since their usage can decrease the web pages' loading time, on average 43.1% with HTTP/2 and 38.5% with QUIC, when requesting a second time the same home page.