A Deep Dive Into SameSite Cookies, What They Are and Why They Matter - Stephen Rees-Carter

This session is from NDC Sydney 2020 Although they’ve been around for years, SameSite cookies hadn’t gained much attention until September 2019. The Chrome team announced their plans to set ‘SameSite=Lax’ on all cookies without the SameSite attribute in Chrome 80, scheduled to release in February 2020. This rollout has since been delayed due to COVID-19, however the change is still coming, and soon. With many developers still unaware of this setting and how it works, it’s likely to catch a lot of us unawares with broken sites and weird behaviours. In this session we will learn about the SameSite cookie attribute and why it is so important to securing your site. We’ll see why ‘Lax’ is the best default to use, and when you’d want to use ‘Strict’ and ‘None’ instead. Additionally, we will cover the edge cases and weird behaviours that can easily cause confusion and seemingly weird bugs. By the end of the session, you’ll know how to properly configure SameSite on your cookies, to ensure your site takes advantage of the security benefits without breaking expected functionality.