SameSite Cookies Plugin
CSRF-protection for authentication cookies. When enabled, this plugin makes sure the "SameSite" flag is set in authentication cookies.
This plugin adds the “SameSite” cookie flag to WordPress’s authentication cookies. On supported browsers (all current IE, Edge, Chrome, and Firefox), this can effectively prevent all Cross-Site Request Forgery attacks throughout your WordPress site.
SameSite cookie flag support was added to PHP on version 7.3, but this plugin ships with a workaround to support all PHP versions WordPress supports.
There is no administrative UI provided: Activate this plugin, and you are all set!
You can configure the SameSite flag value from your WordPress configuration file. You cna pick a value from Lax (default), Strict, or None. You can read about SameSite cookies here.
To configure the SameSite flag value, edit your WordPress configuration file (wp-config.php), and add the following lines right above /** Sets up WordPress vars and included files. */.
define( 'WP_SAMESITE_COOKIE', 'Lax' ); // Pick from 'Lax', 'Strict', or 'None'. Note that only the authentication cookies are affected. Regular cookies that your installed plugins set will not be affected, nor provide any meaningful value with SameSite flags.
Installation
- Install this plugin as you would with any other plugin.
- Enable it.
- There is no third step – From this point afterward, authentication cookies your WordPress site uses will contain SameSite flag, and you will be protected from CSRF attacks.
If you find this plugin useful, I’d appreciate you leaving a review on the plugin page.
Screenshots
Browser response containing the SameSite attribute in Setcookie headers.
FAQ
Yeah, probably. This plugin uses what’s called “pluggable functions” supported in WordPress to replace wp_set_auth_cookie function.
This means that any other plugin that tampers with the login cookie parameters will override this plugin, and this plugin may not even get a chance to do what it does.
Go to the Login page of your WordPress site, and open your browser’s development tools. Inspect the HTTP POST request made by the browser when you submit the login form. The response headers for Setcookie response headers must contain Samesite=Lax (or the configured value) if the plugin is working.
Note that cookies apart from the authentication cookies are not handled by this plugin, nor it makes sense to add SameSite attribute to them.
See the screenshot as well.
No. PHP 7.3 officially added SameSite cookie support, but this plugin comes with a polyfill to extend support to all previous PHP versions.
Without SameSite cookie, WordPress core and third party plugins must implement their own CSRF checks, which can be overlooked, intentionally ignored, or sometimes not even have thought about, which can be the case for contributed plugin. This plugin attempts to solve this with different take and complement existing solutions.
Changelog
1.5
- Fixes a cookie expiration issue that was reported multiple times in the issue queue. Thanks to Jamie Magin (@jamagin at GitHub).
2.0
- Requires PHP 7.0+
- Requires WordPress 6.2+
- Synced pluggable code from upstream for better compatibility with hooks.
2.1
- Minor readme.txt updates