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docs(cookies): Clarify localhost exception for Secure cookies #41795

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docs(cookies): Clarify localhost exception for Secure cookies #41795

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2 changes: 1 addition & 1 deletion files/en-us/web/http/guides/cookies/index.md
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Expand Up @@ -156,7 +156,7 @@ You can ensure that cookies are sent securely and aren't accessed by unintended
Set-Cookie: id=a3fWa; Expires=Thu, 21 Oct 2021 07:28:00 GMT; Secure; HttpOnly
```

- A cookie with the `Secure` attribute is only sent to the server with an encrypted request over the HTTPS protocol. It's never sent with unsecured HTTP (except on localhost), which means {{Glossary("MitM", "man-in-the-middle")}} attackers can't access it easily. Insecure sites (with `http:` in the URL) can't set cookies with the `Secure` attribute. However, don't assume that `Secure` prevents all access to sensitive information in cookies. For example, someone with access to the client's hard disk (or JavaScript if the `HttpOnly` attribute isn't set) can read and modify the information.
- A cookie with the `Secure` attribute is only sent to the server with an encrypted request over the HTTPS protocol. It's never sent with unsecured HTTP (except on localhost, although this exception is not supported by Safari), which means {{Glossary("MitM", "man-in-the-middle")}} attackers can't access it easily. Insecure sites (with `http:` in the URL) can't set cookies with the `Secure` attribute. However, don't assume that `Secure` prevents all access to sensitive information in cookies. For example, someone with access to the client's hard disk (or JavaScript if the `HttpOnly` attribute isn't set) can read and modify the information.

- A cookie with the `HttpOnly` attribute can't be accessed by JavaScript, for example using {{domxref("Document.cookie")}}; it can only be accessed when it reaches the server. Cookies that persist user sessions for example should have the `HttpOnly` attribute set — it would be really insecure to make them available to JavaScript. This precaution helps mitigate cross-site scripting ([XSS](/en-US/docs/Web/Security/Attacks/XSS)) attacks.

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