Ensures intent by verifying that a user was referred from another admin page with the correct security nonce.

Description

This function ensures the user intends to perform a given action, which helps protect against clickjacking style attacks. It verifies intent, not authorization, therefore it does not verify the user’s capabilities. This should be performed with current_user_can() or similar.

If the nonce value is invalid, the function will exit with an "Are You Sure?" style message.

Parameters

$actionint|stringoptional

The nonce action.

Default:-1

$query_argstringoptional

Key to check for nonce in $_REQUEST. Default '_wpnonce'.

Default:'_wpnonce'

Return

More Information

• Using the function without the $action argument is obsolete and, as of Version 3.2, if WP_DEBUG is set to true, the function will die with an appropriate message (“You should specify a nonce action to be verified by using the first parameter.” is the default).
• As of 2.0.1, the referer is checked only if the $action argument is not specified (or set to the default -1) as a backward compatibility fallback for not using a nonce. A nonce is prefered to unreliable referers and with $action specified the function behaves the same way as wp_verify_nonce() except that it dies after calling wp_nonce_ays() if the nonce is not valid or was not sent.

Source

function check_admin_referer( $action = -1, $query_arg = '_wpnonce' ) {
	if ( -1 === $action ) {
		_doing_it_wrong( __FUNCTION__, __( 'You should specify an action to be verified by using the first parameter.' ), '3.2.0' );
	}

	$adminurl = strtolower( admin_url() );
	$referer  = strtolower( wp_get_referer() );
	$result   = isset( $_REQUEST[ $query_arg ] ) ? wp_verify_nonce( $_REQUEST[ $query_arg ], $action ) : false;

	/**
	 * Fires once the admin request has been validated or not.
	 *
	 * @since 1.5.1
	 *
	 * @param string    $action The nonce action.
	 * @param false|int $result False if the nonce is invalid, 1 if the nonce is valid and generated between
	 *                          0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.
	 */
	do_action( 'check_admin_referer', $action, $result );

	if ( ! $result && ! ( -1 === $action && str_starts_with( $referer, $adminurl ) ) ) {
		wp_nonce_ays( $action );
		die();
	}

	return $result;
}

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Hooks

do_action( ‘check_admin_referer’, string $action, false|int $result )

Fires once the admin request has been validated or not.

Changelog