Ticket #38231: 38231.7.diff

src/wp-admin/includes/file.php

@@ -1112 +1112 @@
  *
  * @since 2.5.0
  * @since 5.2.0 Signature Verification with SoftFail was added.
+ * @since 5.9.0 Support for Content-Disposition filename was added.
  *
  * @param string $url                    The URL of the file to download.
  * @param int    $timeout                The timeout for the request to download the file.
@@ -1182 +1183 @@
                 return new WP_Error( 'http_404', trim( wp_remote_retrieve_response_message( $response ) ), $data );
         }
 
+        $content_disposition = wp_remote_retrieve_header( $response, 'content-disposition' );
+
+        if ( $content_disposition ) {
+                $content_disposition = strtolower( $content_disposition );
+
+                if ( 0 === strpos( $content_disposition, 'attachment; filename=' ) ) {
+                        $tmpfname_disposition = sanitize_file_name( substr( $content_disposition, 21 ) );
+                } else {
+                        $tmpfname_disposition = '';
+                }
+
+                // Potential file name must be valid string
+                if ( $tmpfname_disposition && is_string( $tmpfname_disposition ) && ( 0 === validate_file( $tmpfname_disposition ) ) ) {
+                        if ( rename( $tmpfname, $tmpfname_disposition ) ) {
+                                $tmpfname = $tmpfname_disposition;
+                        }
+
+                        if ( ( $tmpfname !== $tmpfname_disposition ) && file_exists( $tmpfname_disposition ) ) {
+                                unlink( $tmpfname_disposition );
+                        }
+                }
+        }
+
         $content_md5 = wp_remote_retrieve_header( $response, 'content-md5' );
 
         if ( $content_md5 ) {

tests/phpunit/tests/admin/includesFile.php

@@ -78 +78 @@
                 return 5;
         }
 
+        /**
+         * @ticket 38231
+         * @dataProvider data_download_url_should_respect_filename_from_content_disposition_header
+         *
+         * @covers ::download_url
+         *
+         * @param $filter  A callback containing a fake Content-Disposition header.
+         */
+        public function test_download_url_should_respect_filename_from_content_disposition_header( $filter ) {
+                add_filter( 'pre_http_request', array( $this, $filter ), 10, 3 );
+
+                $filename = download_url( 'url_with_content_disposition_header' );
+                $this->assertStringContainsString( 'filename-from-content-disposition-header', $filename );
+                $this->assertFileExists( $filename );
+                $this->unlink( $filename );
+
+                remove_filter( 'pre_http_request', array( $this, $filter ) );
+        }
+
+        /**
+         * Data provider for test_download_url_should_respect_filename_from_content_disposition_header.
+         *
+         * @return array
+         */
+        public function data_download_url_should_respect_filename_from_content_disposition_header() {
+                return array(
+                        'valid parameters' => array( 'filter_content_disposition_header_with_filename' ),
+                        'path traversal'   => array( 'filter_content_disposition_header_with_filename_with_path_traversal' ),
+                        'no quotes'        => array( 'filter_content_disposition_header_with_filename_without_quotes' ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_respect_filename_from_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'attachment; filename="filename-from-content-disposition-header.txt"',
+                        ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_respect_filename_from_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename_with_path_traversal( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'attachment; filename="../../filename-from-content-disposition-header.txt"',
+                        ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_respect_filename_from_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename_without_quotes( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'attachment; filename=filename-from-content-disposition-header.txt',
+                        ),
+                );
+        }
+
+        /**
+         * @ticket 38231
+         * @dataProvider data_download_url_should_reject_filename_from_invalid_content_disposition_header
+         *
+         * @covers ::download_url
+         *
+         * @param $filter  A callback containing a fake Content-Disposition header.
+         */
+        public function test_download_url_should_reject_filename_from_invalid_content_disposition_header( $filter ) {
+                add_filter( 'pre_http_request', array( $this, $filter ), 10, 3 );
+
+                $filename = download_url( 'url_with_content_disposition_header' );
+                $this->assertStringContainsString( 'url_with_content_disposition_header', $filename );
+                $this->unlink( $filename );
+
+                remove_filter( 'pre_http_request', array( $this, $filter ) );
+        }
+
+        /**
+         * Data provider for test_download_url_should_reject_filename_from_invalid_content_disposition_header.
+         *
+         * @return array
+         */
+        public function data_download_url_should_reject_filename_from_invalid_content_disposition_header() {
+                return array(
+                        'no context'        => array( 'filter_content_disposition_header_with_filename_without_context' ),
+                        'inline context'    => array( 'filter_content_disposition_header_with_filename_with_inline_context' ),
+                        'form-data context' => array( 'filter_content_disposition_header_with_filename_with_form_data_context' ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_reject_filename_from_invalid_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename_without_context( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'filename="filename-from-content-disposition-header.txt"',
+                        ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_reject_filename_from_invalid_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename_with_inline_context( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'inline; filename="filename-from-content-disposition-header.txt"',
+                        ),
+                );
+        }
+
+        /**
+         * Filter callback for data_download_url_should_reject_filename_from_invalid_content_disposition_header.
+         *
+         * @since 5.9.0
+         *
+         * @return array
+         */
+        public function filter_content_disposition_header_with_filename_with_form_data_context( $response, $args, $url ) {
+                return array(
+                        'response' => array(
+                                'code' => 200,
+                        ),
+                        'headers'  => array(
+                                'content-disposition' => 'form-data; name="file"; filename="filename-from-content-disposition-header.txt"',
+                        ),
+                );
+        }
+
         /**
          * Verify that a WP_Error object is returned when invalid input is passed as the `$url` parameter.
          *