\n This is a cross-post from the
\n Chromium developer blog<\/a>
\n and is specific to how changes to Chrome may affect how your website works for your users in the future.
\n <\/i>\n <\/p>\n
\n In May, Chrome announced<\/a> \n Chrome plans to implement the new model with Chrome 80 in February 2020. Mozilla and Microsoft \n Websites typically integrate external services for advertising, content recommendations, third \n Less obvious cross-site use cases include situations where an entity that owns multiple websites \n \n In contrast, cookie access in a \n \n Today, if a cookie is only intended to be accessed in a first party context, the developer has \n To safeguard more websites and their users, the new secure-by-default model assumes all cookies \n Beyond the immediate security benefits, the explicit declaration of cross-site cookies enables \n With Chrome 80 in February, Chrome will treat cookies that have no declared SameSite value as \n Mozilla has affirmed their support of the new cookie classification model with their \n If you manage cross-site cookies, you will need to apply the
\n a secure-by-default model for cookies, enabled by a new cookie classification system
\n (spec<\/a>). This
\n initiative is part of our
\n ongoing effort<\/a>
\n to improve privacy and security across the web.\n <\/p>\n
\n have also indicated intent to implement the new model in Firefox and Edge, on their own
\n timelines. While the Chrome changes are still a few months away, It’s important that developers
\n who manage cookies assess their readiness today. This blog post outlines high level concepts; please see
\n SameSite Cookies Explained<\/a> on web.dev
\n for developer guidance.\n <\/p>\n\n Understanding Cross-Site and Same-Site Cookie Context
\n <\/h2>\n
\n party widgets, social embeds and other features. As you browse the web, these external services
\n may store cookies in your browser and subsequently access those cookies to deliver personalized
\n experiences or measure audience engagement. Every cookie has a domain associated with it. If
\n the domain associated with a cookie matches an external service and not the website in the
\n user’s address bar, this is considered a cross-site<\/b> (or “third party”<\/b>) context.\n <\/p>\n
\n uses a cookie across those properties. Although the same entity owns the cookie and the
\n websites, this still counts as cross-site or “third party” context when the cookie’s domain
\n does not match the site(s) from which the cookie is accessed.\n<\/p>\n![\"Site](\"https:\/\/alienroad.com\/wp-content\/uploads\/kb-gorsel\/g-aa9da0c01a0a.png\")
<\/p>\n
\n When an external resource on a web page accesses a cookie that does not match the site domain,
\n this is cross-site or “third-party” context.
\n <\/i>\n <\/p>\n
\n same-site<\/b> (or “first party”<\/b>) context occurs when a cookie’s domain matches the
\n website domain in the user’s address bar. Same-site cookies are commonly used to keep people
\n logged into individual websites, remember their preferences and support site analytics.\n <\/p>\n![\"Site](\"https:\/\/alienroad.com\/wp-content\/uploads\/kb-gorsel\/g-a82cbcf669f1.png\")
<\/p>\n
\n When a resource on a web page accesses a cookie that matches the site the user is visiting, this
\n is same-site or “first party” context.
\n <\/i>\n <\/p>\n\n A New Model for Cookie Security and Transparency
\n <\/h2>\n
\n the option to apply one of two settings (SameSite=Lax<\/code> ou
\n SameSite=Strict<\/code>) to prevent external access. However, very few
\n developers follow this recommended practice, leaving a large number of same-site cookies
\n needlessly exposed to threats such as
\n Cross-Site Request Forgery<\/a>
\n attacks.\n <\/p>\n
\n should be protected from external access unless otherwise specified. Developers must use a new
\n cookie setting, SameSite=None<\/code>, to designate cookies for cross-site
\n access. When the SameSite=None<\/code> attribute is present, an additional
\n Secure attribute must be used so cross-site cookies can only be accessed over HTTPS connections.
\n This won’t mitigate all risks associated with cross-site access but it will provide protection
\n against network attacks.\n <\/p>\n
\n greater transparency and user choice. For example, browsers could offer users fine-grained
\n controls to manage cookies that are only accessed by a single site separately from cookies
\n accessed across multiple sites.\n <\/p>\n\n Chrome Enforcement Starting in February 2020
\n <\/h2>\n
\n SameSite=Lax<\/code> cookies. Only cookies with the
\n SameSite=None; Secure<\/code> setting will be available for external
\n access, provided they are being accessed from secure connections. The Chrome Platform Status trackers for
\n SameSite=None<\/code><\/a>
\n and
\n Secure<\/a>
\n will continue to be updated with the latest launch information.\n <\/p>\n
\n intent to implement<\/a>
\n the SameSite=None; Secure<\/code> requirements for cross-site cookies in Firefox. Microsoft recently
\n announced<\/a>
\n plans to begin implementing the model starting as an experiment in Microsoft Edge 80.\n <\/p>\n\n How to Prepare; Known Complexities
\n <\/h2>\nSameSite=None<\/code>;
\n Secure setting to those cookies. Implementation should be straightforward for most developers,
\n but we strongly encourage you to begin testing now to identify complexities and special cases,
\n such as the following:\n <\/p>\n\n
\n cookie header directly. This GitHub repository<\/a>
\n provides instructions for implementing SameSite=None; Secure<\/code> in a
\n variety of languages, libraries and frameworks.\n <\/li>\n
\n None<\/code> value in unintended ways, requiring developers to code
\n exceptions for those clients. This includes Android WebViews powered by older versions of
\n Chrome. Here’s a list of known
\n incompatible clients<\/a>.\n <\/li>\nSameSite cookie<\/code>
\n settings for Android WebViews<\/code> based on versions of Chrome that are
\n compatible with the None<\/code> value, both for cookies accessed via HTTP(S) headers and via Android
\n WebView<\/code>‘s
\n CookieManager API<\/a>,
\n although the new model will not be enforced on Android WebView until later.\n <\/li>\n
\n to temporarily revert Chrome Browser to legacy behavior if some services such as single sign-on or internal applications are not ready for the February launch.\n <\/li>\n
\n using separate cookies to get the security benefits of SameSite=Lax<\/code>
\n in the first-party context.\n <\/li>\n<\/ul>\n
![\"A](\"https:\/\/alienroad.com\/wp-content\/uploads\/kb-gorsel\/g-204966b99640.png\")
<\/p>\n