Sensitive Cookie with Improper SameSite Attribute

Opis

The SameSite attribute for sensitive cookies is not set, or an insecure value is used.

The SameSite attribute controls how cookies are sent for cross-domain requests. This attribute may have three values: 'Lax', 'Strict', or 'None'. If the 'None' value is used, a website may create a cross-domain POST HTTP request to another website, and the browser automatically adds cookies to this request. This may lead to Cross-Site-Request-Forgery (CSRF) attacks if there are no additional protections in place (such as Anti-CSRF tokens).

Skutki

• Confidentiality, Integrity, Non-Repudiation, Access Control

  Modify Application Data

  If the website does not impose additional defense against CSRF attacks, failing to use the 'Lax' or 'Strict' values could increase the risk of exposure to CSRF attacks. The likelihood of the integrity breach is Low because a successful attack does not only depend on an insecure SameSite attribute. In order to perform a CSRF attack there are many conditions that must be met, such as the lack of CSRF tokens, no confirmations for sensitive actions on the website, a "simple" "Content-Type" header in the HTTP request and many more.

Zapobieganie

• Implementation

  Set the SameSite attribute of a sensitive cookie to 'Lax' or 'Strict'. This instructs the browser to apply this cookie only to same-domain requests, which provides a good Defense in Depth against CSRF attacks. When the 'Lax' value is in use, cookies are also sent for top-level cross-domain navigation via HTTP GET, HEAD, OPTIONS, and TRACE methods, but not for other HTTP methods that are more like to cause side-effects of state mutation.

  Skuteczność: High

Przykłady podatności

• CVE-2022-24045 Web application for a room automation system has client-side JavaScript that sets a sensitive cookie without the SameSite security attribute, allowing the cookie to be sniffed

Słabość nadrzędna

• CWE-923 Improper Restriction of Communication Channel to Intended Endpoints

Może prowadzić do

• CWE-352 Cross-Site Request Forgery (CSRF)

Kiedy powstaje

• Implementation — This weakness occurs during implementation when the coder does not properly set the SameSite attribute.

Dotyczy

Not Language-Specific, Not OS-Specific, Not Architecture-Specific, Web Based, Web Server

Źródła

1. SameSite attribute specification draft — M. West, M. Goodwin, 2016
2. SameSite attribute description on MDN Web Docs — Mozilla, 2020
3. Chromium support for SameSite attribute — The Chromium Projects, 2019