ADC

SameSite cookie attribute

For secure web communication, Google has mandated the usage of the SameSite cookie attribute. By complying with Google Chrome’s new SameSite policy, the Citrix ADC appliance can manage third-party cookies with the SameSite attribute set in the set-cookie header. The cookie setting mitigates attacks and provides a secured web communication.

Until February 2020, the SameSite attribute was not explicitly set in the cookie. The browser took the default value as “None.” However, with certain browser upgrade, such as Google Chrome 80, there is a change in the default cross-domain behavior in cookies.

The SameSite attribute is set to one of the following values and for the Google Chrome browser, the default value is set as “Lax.”

None. Indicates the browser to use the cookie for requests in the cross-site context only on secure connections.

Lax. Indicates the browser to use the cookie for requests in the same-site context. In the cross-site context, only safe HTTP methods like GET request can use the cookie.

Strict. Use the cookie only when the user is requesting for the domain explicitly.

Note:

If set-cookies (including firewall session cookies) have the SameSite attribute and if the addcookiesamesite attribute flag is enabled in the Web Application Firewall profile, then the SameSite attribute is overwritten according to the value configured in the profile.

Configure the SameSite attribute in the Web App Firewall profile by using the CLI

To configure the SameSite attribute, you must complete the following steps:

  1. Enable the SameSite cookie attribute.
  2. Set the cookie attribute for the appfw session cookies.

At the command prompt, type:

set appfw profile <profile-name> –insertCookieSameSiteAttribute \( ON | OFF)

Example:

set appfw profile p1 –insertCookieSameSiteAttribute ON

At the command prompt, type:

set appfw profile <profile-name> – cookieSameSiteAttribute \( LAX | NONE | STRICT )

Example:

set appfw profile p1 – cookieSameSiteAttribute LAX

Where attribute types are,

None. Cookie attribute SameSite is set to “none” and marked secure for all WAF and application cookies.

Lax. Cookie attribute SameSite is set to “Lax” for all WAF and application cookies.

Strict. Cookie attribute SameSite is set to “Lax” for all WAF and application cookies.

  1. Navigate to Security > Citrix Web App Firewall > Profiles.
  2. In the details pane, select a profile and click Edit.
  3. In the Citrix Web App Firewall Profile page, click Profile Settings under Advanced Settings.
  4. In Profile Settings section set the following parameters:

    a. Insert the cookie Samesite attribute. Select the check box to enable the cookie Samesite attribute. b. Cookie Samesite Attribute. Select an option from the drop-down list to set the Samesite cookie value.

  5. Click OK and Done.

SameSite cookie attribute settings on Citrix ADC GUI

SameSite cookie attribute