Changeset 47633

Timestamp:

04/29/2020 03:12:50 PM (6 years ago)

Author:

whyisjake

Message:

Customize: Add additional filters to Customizer to prevent JSON corruption.

This solution extends the wp_insert_post_data filter to pass in addition to the slashed/sanitized/processed data, and the slashed/sanitized/unprocessed data, to also pass the initial slashed/unsanitized/unprocessed data which was passed into wp_insert_post(). This then allows plugins to have complete control over how sanitization is performed based on the post type.

Props westonruter, peterwilsoncc, sstoqnov, whyisjake, xknown.

Location:

trunk

Files:

• src/wp-includes/class-wp-customize-manager.php (modified) (3 diffs)
• src/wp-includes/post.php (modified) (3 diffs)
• tests/phpunit/tests/customize/manager.php (modified) (1 diff)

trunk/src/wp-includes/class-wp-customize-manager.php

@@ -2929 +2929 @@
                  */
 
-                // Prevent content filters from corrupting JSON in post_content.
-                $has_kses = ( false !== has_filter( 'content_save_pre', 'wp_filter_post_kses' ) );
-                if ( $has_kses ) {
-                        kses_remove_filters();
-                }
-                $has_targeted_link_rel_filters = ( false !== has_filter( 'content_save_pre', 'wp_targeted_link_rel' ) );
-                if ( $has_targeted_link_rel_filters ) {
-                        wp_remove_targeted_link_rel_filters();
-                }
-
-                // Note that updating a post with publish status will trigger WP_Customize_Manager::publish_changeset_values().
+                /*
+                 * Update the changeset post. The publish_customize_changeset action will cause the settings in the
+                 * changeset to be saved via WP_Customize_Setting::save(). Updating a post with publish status will
+                 * trigger WP_Customize_Manager::publish_changeset_values().
+                 */
+                add_filter( 'wp_insert_post_data', array( $this, 'preserve_insert_changeset_post_content' ), 5, 3 );
                 if ( $changeset_post_id ) {
                         if ( $args['autosave'] && 'auto-draft' !== get_post_status( $changeset_post_id ) ) {
@@ -2970 +2965 @@
                         }
                 }
-
-                // Restore removed content filters.
-                if ( $has_kses ) {
-                        kses_init_filters();
-                }
-                if ( $has_targeted_link_rel_filters ) {
-                        wp_init_targeted_link_rel_filters();
-                }
+                remove_filter( 'wp_insert_post_data', array( $this, 'preserve_insert_changeset_post_content' ), 5 );
 
                 $this->_changeset_data = null; // Reset so WP_Customize_Manager::changeset_data() will re-populate with updated contents.
@@ -2993 +2981 @@
 
                 return $response;
+        }
+
+        /**
+         * Preserve the initial JSON post_content passed to save into the post.
+         *
+         * This is needed to prevent KSES and other {@see 'content_save_pre'} filters
+         * from corrupting JSON data.
+         *
+         * Note that WP_Customize_Manager::validate_setting_values() have already
+         * run on the setting values being serialized as JSON into the post content
+         * so it is pre-sanitized.
+         *
+         * Also, the sanitization logic is re-run through the respective
+         * WP_Customize_Setting::sanitize() method when being read out of the
+         * changeset, via WP_Customize_Manager::post_value(), and this sanitized
+         * value will also be sent into WP_Customize_Setting::update() for
+         * persisting to the DB.
+         *
+         * Multiple users can collaborate on a single changeset, where one user may
+         * have the unfiltered_html capability but another may not. A user with
+         * unfiltered_html may add a script tag to some field which needs to be kept
+         * intact even when another user updates the changeset to modify another field
+         * when they do not have unfiltered_html.
+         *
+         * @since 5.4.1
+         *
+         * @param array $data                An array of slashed and processed post data.
+         * @param array $postarr             An array of sanitized (and slashed) but otherwise unmodified post data.
+         * @param array $unsanitized_postarr An array of slashed yet *unsanitized* and unprocessed post data as originally passed to wp_insert_post().
+         * @return array Filtered post data.
+         */
+        public function preserve_insert_changeset_post_content( $data, $postarr, $unsanitized_postarr ) {
+                if (
+                        isset( $data['post_type'] ) &&
+                        isset( $unsanitized_postarr['post_content'] ) &&
+                        'customize_changeset' === $data['post_type'] ||
+                        (
+                                'revision' === $data['post_type'] &&
+                                ! empty( $data['post_parent'] ) &&
+                                'customize_changeset' === get_post_type( $data['post_parent'] )
+                        )
+                ) {
+                        $data['post_content'] = $unsanitized_postarr['post_content'];
+                }
+                return $data;
         }
 

trunk/src/wp-includes/post.php

@@ -3595 +3595 @@
         global $wpdb;
 
+        // Capture original pre-sanitized array for passing into filters.
+        $unsanitized_postarr = $postarr;
+
         $user_id = get_current_user_id();
 
@@ -3919 +3922 @@
                  *
                  * @since 3.9.0
+                 * @since 5.4.1 `$unsanitized_postarr` argument added.
                  *
-                 * @param array $data    An array of sanitized attachment post data.
-                 * @param array $postarr An array of unsanitized attachment post data.
+                 * @param array $data                An array of slashed, sanitized, and processed attachment post data.
+                 * @param array $postarr             An array of slashed and sanitized attachment post data, but not processed.
+                 * @param array $unsanitized_postarr An array of slashed yet *unsanitized* and unprocessed attachment post data
+                 *                                   as originally passed to wp_insert_post().
                  */
-                $data = apply_filters( 'wp_insert_attachment_data', $data, $postarr );
+                $data = apply_filters( 'wp_insert_attachment_data', $data, $postarr, $unsanitized_postarr );
         } else {
                 /**
@@ -3929 +3935 @@
                  *
                  * @since 2.7.0
+                 * @since 5.4.1 `$unsanitized_postarr` argument added.
                  *
-                 * @param array $data    An array of slashed post data.
-                 * @param array $postarr An array of sanitized, but otherwise unmodified post data.
+                 * @param array $data                An array of slashed, sanitized, and processed post data.
+                 * @param array $postarr             An array of sanitized (and slashed) but otherwise unmodified post data.
+                 * @param array $unsanitized_postarr An array of slashed yet *unsanitized* and unprocessed post data as
+                 *                                   originally passed to wp_insert_post().
                  */
-                $data = apply_filters( 'wp_insert_post_data', $data, $postarr );
+                $data = apply_filters( 'wp_insert_post_data', $data, $postarr, $unsanitized_postarr );
         }
         $data  = wp_unslash( $data );

trunk/tests/phpunit/tests/customize/manager.php

@@ -1242 +1242 @@
 
         /**
+         * Test saving changeset post without Kses or other content_save_pre filters mutating content.
+         *
+         * @covers WP_Customize_Manager::save_changeset_post()
+         */
+        public function test_save_changeset_post_without_kses_corrupting_json() {
+                global $wp_customize;
+                $lesser_admin_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+
+                $uuid         = wp_generate_uuid4();
+                $wp_customize = new WP_Customize_Manager(
+                        array(
+                                'changeset_uuid' => $uuid,
+                        )
+                );
+
+                add_filter( 'map_meta_cap', array( $this, 'filter_map_meta_cap_to_disallow_unfiltered_html' ), 10, 2 );
+                kses_init();
+                add_filter( 'content_save_pre', 'capital_P_dangit' );
+                add_post_type_support( 'customize_changeset', 'revisions' );
+
+                $options = array(
+                        'custom_html_1' => '<script>document.write(" Wordpress 1")</script>',
+                        'custom_html_2' => '<script>document.write(" Wordpress 2")</script>',
+                        'custom_html_3' => '<script>document.write(" Wordpress 3")</script>',
+                );
+
+                // Populate setting as user who can bypass content_save_pre filter.
+                wp_set_current_user( self::$admin_user_id );
+                $wp_customize = $this->get_manager_for_testing_json_corruption_protection( $uuid );
+                $wp_customize->set_post_value( 'custom_html_1', $options['custom_html_1'] );
+                $wp_customize->save_changeset_post(
+                        array(
+                                'status' => 'draft',
+                        )
+                );
+
+                // Populate setting as user who cannot bypass content_save_pre filter.
+                wp_set_current_user( $lesser_admin_user_id );
+                $wp_customize = $this->get_manager_for_testing_json_corruption_protection( $uuid );
+                $wp_customize->set_post_value( 'custom_html_2', $options['custom_html_2'] );
+                $wp_customize->save_changeset_post(
+                        array(
+                                'autosave' => true,
+                        )
+                );
+
+                /*
+                 * Ensure that the unsanitized value (the "POST data") is preserved in the autosave revision.
+                 * The value is sent through the sanitize function when it is read from the changeset.
+                 */
+                $autosave_revision = wp_get_post_autosave( $wp_customize->changeset_post_id(), get_current_user_id() );
+                $saved_data        = json_decode( $autosave_revision->post_content, true );
+                $this->assertEquals( $options['custom_html_1'], $saved_data['custom_html_1']['value'] );
+                $this->assertEquals( $options['custom_html_2'], $saved_data['custom_html_2']['value'] );
+
+                // Update post to discard autosave.
+                $wp_customize->save_changeset_post(
+                        array(
+                                'status' => 'draft',
+                        )
+                );
+
+                /*
+                 * Ensure that the unsanitized value (the "POST data") is preserved in the post content.
+                 * The value is sent through the sanitize function when it is read from the changeset.
+                 */
+                $wp_customize = $this->get_manager_for_testing_json_corruption_protection( $uuid );
+                $saved_data   = json_decode( get_post( $wp_customize->changeset_post_id() )->post_content, true );
+                $this->assertEquals( $options['custom_html_1'], $saved_data['custom_html_1']['value'] );
+                $this->assertEquals( $options['custom_html_2'], $saved_data['custom_html_2']['value'] );
+
+                /*
+                 * Ensure that the unsanitized value (the "POST data") is preserved in the revisions' content.
+                 * The value is sent through the sanitize function when it is read from the changeset.
+                 */
+                $revisions  = wp_get_post_revisions( $wp_customize->changeset_post_id() );
+                $revision   = array_shift( $revisions );
+                $saved_data = json_decode( $revision->post_content, true );
+                $this->assertEquals( $options['custom_html_1'], $saved_data['custom_html_1']['value'] );
+                $this->assertEquals( $options['custom_html_2'], $saved_data['custom_html_2']['value'] );
+
+                /*
+                 * Now when publishing the changeset, the unsanitized values will be read from the changeset
+                 * and sanitized according to the capabilities of the users who originally updated each
+                 * setting in the changeset to begin with.
+                 */
+                wp_set_current_user( $lesser_admin_user_id );
+                $wp_customize = $this->get_manager_for_testing_json_corruption_protection( $uuid );
+                $wp_customize->set_post_value( 'custom_html_3', $options['custom_html_3'] );
+                $wp_customize->save_changeset_post(
+                        array(
+                                'status' => 'publish',
+                        )
+                );
+
+                // User saved as one who can bypass content_save_pre filter.
+                $this->assertContains( '<script>', get_option( 'custom_html_1' ) );
+                $this->assertContains( 'Wordpress', get_option( 'custom_html_1' ) ); // phpcs:ignore WordPress.WP.CapitalPDangit.Misspelled
+
+                // User saved as one who cannot bypass content_save_pre filter.
+                $this->assertNotContains( '<script>', get_option( 'custom_html_2' ) );
+                $this->assertContains( 'WordPress', get_option( 'custom_html_2' ) );
+
+                // User saved as one who also cannot bypass content_save_pre filter.
+                $this->assertNotContains( '<script>', get_option( 'custom_html_3' ) );
+                $this->assertContains( 'WordPress', get_option( 'custom_html_3' ) );
+        }
+
+        /**
+         * Get a manager for testing JSON corruption protection.
+         *
+         * @param string $uuid UUID.
+         * @return WP_Customize_Manager Manager.
+         */
+        private function get_manager_for_testing_json_corruption_protection( $uuid ) {
+                global $wp_customize;
+                $wp_customize = new WP_Customize_Manager(
+                        array(
+                                'changeset_uuid' => $uuid,
+                        )
+                );
+                for ( $i = 0; $i < 5; $i++ ) {
+                        $wp_customize->add_setting(
+                                sprintf( 'custom_html_%d', $i ),
+                                array(
+                                        'type'              => 'option',
+                                        'sanitize_callback' => array( $this, 'apply_content_save_pre_filters_if_not_main_admin_user' ),
+                                )
+                        );
+                }
+                return $wp_customize;
+        }
+
+        /**
+         * Sanitize content with Kses if the current user is not the main admin.
+         *
+         * @since 5.2.?
+         *
+         * @param string $content Content to sanitize.
+         * @return string Sanitized content.
+         */
+        public function apply_content_save_pre_filters_if_not_main_admin_user( $content ) {
+                if ( get_current_user_id() !== self::$admin_user_id ) {
+                        $content = apply_filters( 'content_save_pre', $content );
+                }
+                return $content;
+        }
+
+        /**
+         * Filter map_meta_cap to disallow unfiltered_html.
+         *
+         * @since 5.2.?
+         *
+         * @param array  $caps User's capabilities.
+         * @param string $cap  Requested cap.
+         * @return array Caps.
+         */
+        public function filter_map_meta_cap_to_disallow_unfiltered_html( $caps, $cap ) {
+                if ( 'unfiltered_html' === $cap ) {
+                        $caps = array( 'do_not_allow' );
+                }
+                return $caps;
+        }
+
+        /**
          * Call count for customize_changeset_save_data filter.
          *