Secure cookie
Type of HTTP cookie
Secure cookie is a type of an HTTP cookie that has the Secure attribute set, which limits the scope of the cookie to "secure" channels (where "secure" is defined by the user agent, typically web browser). When a cookie has the Secure attribute, the user agent will include the cookie in an HTTP request only if the request is transmitted over a secure channel (typically HTTPS).
Although seemingly useful for protecting cookies from active network attackers, the Secure attribute protects only the cookie's confidentiality. An active network attacker can overwrite Secure cookies from an insecure channel, disrupting their integrity. This issue is officially referred to as Weak Integrity. However, some browsers, including Chrome 52 and higher and Firefox 52 and higher, forgo this specification in favor of better security and forbid insecure sites (HTTP) from setting cookies with the Secure directive.
Even with Secure, some sources recommend that sensitive information never be stored in cookies, on the premise that they are inherently insecure and this flag can't offer real protection. Secure attribute is not the only protection mechanism for cookies, there are also HttpOnly and SameSite attributes. The HttpOnly attribute restricts the cookie from being accessed by, for instance, JavaScript, while the SameSite attribute only allows the cookie to be sent to the application if the request originated from the same domain.
01Background
An HTTP cookie is a small packet of data that is sent from a web server to a user's web browser. There are two types of cookie:
- Persistent cookies - Cookies that store information in the user's browser for a long time.
- Non-persistent cookies - Cookies that generally expire when the browser closes.
Cookies could contain sensitive information, such as passwords and credit card numbers, which are sent over an HTTP connection and might be stored in web browsers as plain text. To prevent attackers from stealing this information, cookies can be secured with attributes.
Sources and credits
This article is adapted from the Wikipedia article “Secure cookie”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
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