Merge branch 'hardening'

CHANGELOG.md

@@ -9,11 +9,15 @@
     * ADDED: Google Cloud Storage backend support (#795)
     * ADDED: Oracle database support (#868)
     * ADDED: Configuration option to limit paste creation and commenting to certain IPs (#883)
+    * ADDED: Set CSP also as meta tag, to deal with misconfigured webservers mangling the HTTP header
+    * ADDED: Sanitize SVG preview, preventing script execution in instance context
     * CHANGED: Language selection cookie only transmitted over HTTPS (#472)
-    * CHANGED: Upgrading libraries to: base-x 4.0.0, bootstrap 3.4.1 (JS), DOMpurify 2.3.6, ip-lib 1.18.0, jQuery 3.6.0, random_compat 2.0.21 & Showdown 2.0.0
+    * CHANGED: Upgrading libraries to: base-x 4.0.0, bootstrap 3.4.1 (JS), DOMpurify 2.3.6, ip-lib 1.18.0, jQuery 3.6.0, random_compat 2.0.21 & Showdown 2.0.3
     * CHANGED: Removed automatic `.ini` configuration file migration (#808)
     * CHANGED: Removed configurable `dir` for `traffic` & `purge` limiters (#419)
     * CHANGED: Server salt, traffic and purge limiter now stored in the storage backend (#419)
+    * CHANGED: Drop support for attachment download in IE
+    * FIXED: Error when attachments are disabled, but paste with attachment gets displayed
   * **1.3.5 (2021-04-05)**
     * ADDED: Translations for Hebrew, Lithuanian, Indonesian and Catalan
     * ADDED: Make the project info configurable (#681)

cfg/conf.sample.php

@@ -87,7 +87,7 @@ languageselection = false
 ;   async functions and display an error if not and for Chrome to enable
 ;   webassembly support (used for zlib compression). You can remove it if Chrome
 ;   doesn't need to be supported and old browsers don't need to be warned.
-; cspheader = "default-src 'none'; base-uri 'self'; form-action 'none'; manifest-src 'self'; connect-src * blob:; script-src 'self' 'unsafe-eval' resource:; style-src 'self'; font-src 'self'; frame-ancestors 'none'; img-src 'self' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads"
+; cspheader = "default-src 'none'; base-uri 'self'; form-action 'none'; manifest-src 'self'; connect-src * blob:; script-src 'self' 'unsafe-eval'; style-src 'self'; font-src 'self'; frame-ancestors 'none'; img-src 'self' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads"
 
 ; stay compatible with PrivateBin Alpha 0.19, less secure
 ; if enabled will use base64.js version 1.7 instead of 2.1.9 and sha1 instead of

js/common.js

@@ -16,7 +16,7 @@ global.zlib = require('./zlib-1.2.11').zlib;
 require('./prettify');
 global.prettyPrint = window.PR.prettyPrint;
 global.prettyPrintOne = window.PR.prettyPrintOne;
-global.showdown = require('./showdown-2.0.0');
+global.showdown = require('./showdown-2.0.3');
 global.DOMPurify = require('./purify-2.3.6');
 global.baseX = require('./base-x-4.0.0').baseX;
 global.Legacy = require('./legacy').Legacy;

js/privatebin.js

@@ -52,6 +52,31 @@ jQuery.PrivateBin = (function($, RawDeflate) {
      */
     let z;
 
+    /**
+     * DOMpurify settings for HTML content
+     *
+     * @private
+     */
+     const purifyHtmlConfig = {
+        ALLOWED_URI_REGEXP: /^(?:(?:(?:f|ht)tps?|mailto|magnet):)/i,
+        SAFE_FOR_JQUERY: true,
+        USE_PROFILES: {
+            html: true
+        }
+    };
+
+    /**
+     * DOMpurify settings for SVG content
+     *
+     * @private
+     */
+     const purifySvgConfig = {
+        USE_PROFILES: {
+            svg: true,
+            svgFilters: true
+        }
+    };
+
     /**
      * CryptoData class
      *
@@ -409,7 +434,8 @@ jQuery.PrivateBin = (function($, RawDeflate) {
                     element.html().replace(
                         /(((https?|ftp):\/\/[\w?!=&.\/-;#@~%+*-]+(?![\w\s?!&.\/;#~%"=-]>))|((magnet):[\w?=&.\/-;#@~%+*-]+))/ig,
                         '<a href="$1" rel="nofollow noopener noreferrer">$1</a>'
-                    )
+                    ),
+                    purifyHtmlConfig
                 )
             );
         };
@@ -2536,7 +2562,8 @@ jQuery.PrivateBin = (function($, RawDeflate) {
                 // let showdown convert the HTML and sanitize HTML *afterwards*!
                 $plainText.html(
                     DOMPurify.sanitize(
-                        converter.makeHtml(text)
+                        converter.makeHtml(text),
+                        purifyHtmlConfig
                     )
                 );
                 // add table classes from bootstrap css
@@ -2752,6 +2779,34 @@ jQuery.PrivateBin = (function($, RawDeflate) {
             $dropzone;
 
         /**
+         * get blob URL from string data and mime type
+         *
+         * @name   AttachmentViewer.getBlobUrl
+         * @private
+         * @function
+         * @param {string} data - raw data of attachment
+         * @param {string} data - mime type of attachment
+         * @return {string} objectURL
+         */
+         function getBlobUrl(data, mimeType)
+         {
+            // Transform into a Blob
+            const buf = new Uint8Array(data.length);
+            for (let i = 0; i < data.length; ++i) {
+                buf[i] = data.charCodeAt(i);
+            }
+            const blob = new window.Blob(
+                [buf],
+                {
+                    type: mimeType
+                }
+            );
+
+            // Get blob URL
+            return window.URL.createObjectURL(blob);
+         }
+
+         /**
          * sets the attachment but does not yet show it
          *
          * @name   AttachmentViewer.setAttachment
@@ -2761,44 +2816,42 @@ jQuery.PrivateBin = (function($, RawDeflate) {
          */
         me.setAttachment = function(attachmentData, fileName)
         {
-            // data URI format: data:[<mediaType>][;base64],<data>
+            // skip, if attachments got disabled
+            if (!$attachmentLink || !$attachmentPreview) return;
+
+            // data URI format: data:[<mimeType>][;base64],<data>
 
             // position in data URI string of where data begins
             const base64Start = attachmentData.indexOf(',') + 1;
-            // position in data URI string of where mediaType ends
+            // position in data URI string of where mimeType ends
-            const mediaTypeEnd = attachmentData.indexOf(';');
+            const mimeTypeEnd = attachmentData.indexOf(';');
 
-            // extract mediaType
+            // extract mimeType
-            const mediaType = attachmentData.substring(5, mediaTypeEnd);
+            const mimeType = attachmentData.substring(5, mimeTypeEnd);
             // extract data and convert to binary
             const rawData = attachmentData.substring(base64Start);
             const decodedData = rawData.length > 0 ? atob(rawData) : '';
 
-            // Transform into a Blob
+            let blobUrl = getBlobUrl(decodedData, mimeType);
-            const buf = new Uint8Array(decodedData.length);
+            $attachmentLink.attr('href', blobUrl);
-            for (let i = 0; i < decodedData.length; ++i) {
-                buf[i] = decodedData.charCodeAt(i);
-            }
-            const blob = new window.Blob([ buf ], { type: mediaType });
-
-            // Get Blob URL
-            const blobUrl = window.URL.createObjectURL(blob);
-
-            // IE does not support setting a data URI on an a element
-            // Using msSaveBlob to download
-            if (window.Blob && navigator.msSaveBlob) {
-                $attachmentLink.off('click').on('click', function () {
-                    navigator.msSaveBlob(blob, fileName);
-                });
-            } else {
-                $attachmentLink.attr('href', blobUrl);
-            }
 
             if (typeof fileName !== 'undefined') {
                 $attachmentLink.attr('download', fileName);
             }
 
-            me.handleBlobAttachmentPreview($attachmentPreview, blobUrl, mediaType);
+            // sanitize SVG preview
+            // prevents executing embedded scripts when CSP is not set and user
+            // right-clicks/long-taps and opens the SVG in a new tab - prevented
+            // in the preview by use of an img tag, which disables scripts, too
+            if (mimeType.match(/^image\/.*svg/i)) {
+                const sanitizedData = DOMPurify.sanitize(
+                    decodedData,
+                    purifySvgConfig
+                );
+                blobUrl = getBlobUrl(sanitizedData, mimeType);
+            }
+
+            me.handleBlobAttachmentPreview($attachmentPreview, blobUrl, mimeType);
         };
 
         /**
@@ -2809,6 +2862,9 @@ jQuery.PrivateBin = (function($, RawDeflate) {
          */
         me.showAttachment = function()
         {
+            // skip, if attachments got disabled
+            if (!$attachment || !$attachmentPreview) return;
+
             $attachment.removeClass('hidden');
 
             if (attachmentHasPreview) {
@@ -3016,13 +3072,13 @@ jQuery.PrivateBin = (function($, RawDeflate) {
         me.handleBlobAttachmentPreview = function ($targetElement, blobUrl, mimeType) {
             if (blobUrl) {
                 attachmentHasPreview = true;
-                if (mimeType.match(/image\//i)) {
+                if (mimeType.match(/^image\//i)) {
                     $targetElement.html(
                         $(document.createElement('img'))
                             .attr('src', blobUrl)
                             .attr('class', 'img-thumbnail')
                     );
-                } else if (mimeType.match(/video\//i)) {
+                } else if (mimeType.match(/^video\//i)) {
                     $targetElement.html(
                         $(document.createElement('video'))
                             .attr('controls', 'true')
@@ -3033,7 +3089,7 @@ jQuery.PrivateBin = (function($, RawDeflate) {
                             .attr('type', mimeType)
                             .attr('src', blobUrl))
                     );
-                } else if (mimeType.match(/audio\//i)) {
+                } else if (mimeType.match(/^audio\//i)) {
                     $targetElement.html(
                         $(document.createElement('audio'))
                             .attr('controls', 'true')
@@ -3665,7 +3721,14 @@ jQuery.PrivateBin = (function($, RawDeflate) {
             for (let i = 0; i < $head.length; ++i) {
                 newDoc.write($head[i].outerHTML);
             }
-            newDoc.write('</head><body><pre>' + DOMPurify.sanitize(Helper.htmlEntities(paste)) + '</pre></body></html>');
+            newDoc.write(
+                '</head><body><pre>' +
+                DOMPurify.sanitize(
+                    Helper.htmlEntities(paste),
+                    purifyHtmlConfig
+                ) +
+                '</pre></body></html>'
+            );
             newDoc.close();
         }
 
@@ -5394,11 +5457,6 @@ jQuery.PrivateBin = (function($, RawDeflate) {
             // first load translations
             I18n.loadTranslations();
 
-            DOMPurify.setConfig({
-                ALLOWED_URI_REGEXP: /^(?:(?:(?:f|ht)tps?|mailto|magnet):)/i,
-                SAFE_FOR_JQUERY: true
-            });
-
             // Add a hook to make all links open a new window
             DOMPurify.addHook('afterSanitizeAttributes', function(node) {
                 // set all elements owning target to target=_blank

lib/Configuration.php

@@ -54,7 +54,7 @@ class Configuration
             'urlshortener'             => '',
             'qrcode'                   => true,
             'icon'                     => 'identicon',
-            'cspheader'                => 'default-src \'none\'; base-uri \'self\'; form-action \'none\'; manifest-src \'self\'; connect-src * blob:; script-src \'self\' \'unsafe-eval\' resource:; style-src \'self\'; font-src \'self\'; frame-ancestors \'none\'; img-src \'self\' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads',
+            'cspheader'                => 'default-src \'none\'; base-uri \'self\'; form-action \'none\'; manifest-src \'self\'; connect-src * blob:; script-src \'self\' \'unsafe-eval\'; style-src \'self\'; font-src \'self\'; frame-ancestors \'none\'; img-src \'self\' data: blob:; media-src blob:; object-src blob:; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads',
             'zerobincompatibility'     => false,
             'httpwarning'              => true,
             'compression'              => 'zlib',

lib/Controller.php

@@ -364,6 +364,16 @@ class Controller
             setcookie('lang', $languageselection, 0, '', '', true);
         }
 
+        // strip policies that are unsupported in meta tag
+        $metacspheader = str_replace(
+            array(
+                'frame-ancestors \'none\'; ',
+                '; sandbox allow-same-origin allow-scripts allow-forms allow-popups allow-modals allow-downloads',
+            ),
+            '',
+            $this->_conf->getKey('cspheader')
+        );
+
         $page = new View;
         $page->assign('NAME', $this->_conf->getKey('name'));
         $page->assign('BASEPATH', I18n::_($this->_conf->getKey('basepath')));
@@ -392,6 +402,7 @@ class Controller
         $page->assign('HTTPWARNING', $this->_conf->getKey('httpwarning'));
         $page->assign('HTTPSLINK', 'https://' . $this->_request->getHost() . $this->_request->getRequestUri());
         $page->assign('COMPRESSION', $this->_conf->getKey('compression'));
+        $page->assign('CSPHEADER', $metacspheader);
         $page->draw($this->_conf->getKey('template'));
     }
 

tpl/bootstrap.php

@@ -7,6 +7,7 @@ $isPage = substr($template, -5) === '-page';
 <html lang="<?php echo I18n::_('en'); ?>">
 	<head>
 		<meta charset="utf-8" />
+		<meta http-equiv="Content-Security-Policy" content="<?php echo I18n::encode($CSPHEADER); ?>">
 		<meta http-equiv="X-UA-Compatible" content="IE=edge">
 		<meta name="viewport" content="width=device-width, initial-scale=1">
 		<meta name="robots" content="noindex" />
@@ -66,13 +67,13 @@ if ($SYNTAXHIGHLIGHTING) :
 endif;
 if ($MARKDOWN) :
 ?>
-		<script type="text/javascript" data-cfasync="false" src="js/showdown-2.0.0.js" integrity="sha512-UB9jpMTOJLSnVzePuqlSGT34G70wEGqtIWabMeAh+Drnj4/uQ8rFkFn1zkN9vkWp/7nA51U2LmP23H5MJvBXsw==" crossorigin="anonymous"></script>
+		<script type="text/javascript" data-cfasync="false" src="js/showdown-2.0.3.js" integrity="sha512-vcfjvW3UKHD/4vlQx804cqWK88jFmjsWRsZ8/u5YEcyHB1IituxrXDU7TvdqsFVsMnxpE/UIEo25/SYW+puWHw==" crossorigin="anonymous"></script>
 <?php
 endif;
 ?>
 		<script type="text/javascript" data-cfasync="false" src="js/purify-2.3.6.js" integrity="sha512-N1GGPjbqLbwK821ZN7C925WuTwU4aDxz2CEEOXQ6/s6m6MBwVj8fh5fugiE2hzsm0xud3q7jpjZQ4ILnpMREYQ==" crossorigin="anonymous"></script>
 		<script type="text/javascript" data-cfasync="false" src="js/legacy.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-LYos+qXHIRqFf5ZPNphvtTB0cgzHUizu2wwcOwcwz/VIpRv9lpcBgPYz4uq6jx0INwCAj6Fbnl5HoKiLufS2jg==" crossorigin="anonymous"></script>
-		<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-EdUms2nI12Cmtv014stIEBlyPjeKMHlkg7NiBJup1b7jJF5amKhev2RwTaldINXK4UaWbZtQ6hGuMPNvvNQZFA==" crossorigin="anonymous"></script>
+		<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-kFUoM3Qg6VzRTJGau3wWP2IRZQF2WToL7Dgvazxqp0jgYIKA5cCK9xFy9Zes208XX0nYP64scW2nJIYNk9pL6Q==" crossorigin="anonymous"></script>
 		<!-- icon -->
 		<link rel="apple-touch-icon" href="<?php echo I18n::encode($BASEPATH); ?>img/apple-touch-icon.png" sizes="180x180" />
 		<link rel="icon" type="image/png" href="img/favicon-32x32.png" sizes="32x32" />

tpl/page.php

@@ -4,6 +4,7 @@ use PrivateBin\I18n;
 <html lang="<?php echo I18n::_('en'); ?>">
 	<head>
 		<meta charset="utf-8" />
+		<meta http-equiv="Content-Security-Policy" content="<?php echo I18n::encode($CSPHEADER); ?>">
 		<meta name="robots" content="noindex" />
 		<meta name="google" content="notranslate">
 		<title><?php echo I18n::_($NAME); ?></title>
@@ -44,13 +45,13 @@ if ($SYNTAXHIGHLIGHTING):
 endif;
 if ($MARKDOWN):
 ?>
-		<script type="text/javascript" data-cfasync="false" src="js/showdown-2.0.0.js" integrity="sha512-UB9jpMTOJLSnVzePuqlSGT34G70wEGqtIWabMeAh+Drnj4/uQ8rFkFn1zkN9vkWp/7nA51U2LmP23H5MJvBXsw==" crossorigin="anonymous"></script>
+		<script type="text/javascript" data-cfasync="false" src="js/showdown-2.0.3.js" integrity="sha512-vcfjvW3UKHD/4vlQx804cqWK88jFmjsWRsZ8/u5YEcyHB1IituxrXDU7TvdqsFVsMnxpE/UIEo25/SYW+puWHw==" crossorigin="anonymous"></script>
 <?php
 endif;
 ?>
 		<script type="text/javascript" data-cfasync="false" src="js/purify-2.3.6.js" integrity="sha512-N1GGPjbqLbwK821ZN7C925WuTwU4aDxz2CEEOXQ6/s6m6MBwVj8fh5fugiE2hzsm0xud3q7jpjZQ4ILnpMREYQ==" crossorigin="anonymous"></script>
 		<script type="text/javascript" data-cfasync="false" src="js/legacy.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-LYos+qXHIRqFf5ZPNphvtTB0cgzHUizu2wwcOwcwz/VIpRv9lpcBgPYz4uq6jx0INwCAj6Fbnl5HoKiLufS2jg==" crossorigin="anonymous"></script>
-		<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-EdUms2nI12Cmtv014stIEBlyPjeKMHlkg7NiBJup1b7jJF5amKhev2RwTaldINXK4UaWbZtQ6hGuMPNvvNQZFA==" crossorigin="anonymous"></script>
+		<script type="text/javascript" data-cfasync="false" src="js/privatebin.js?<?php echo rawurlencode($VERSION); ?>" integrity="sha512-kFUoM3Qg6VzRTJGau3wWP2IRZQF2WToL7Dgvazxqp0jgYIKA5cCK9xFy9Zes208XX0nYP64scW2nJIYNk9pL6Q==" crossorigin="anonymous"></script>
 		<!-- icon -->
 		<link rel="apple-touch-icon" href="img/apple-touch-icon.png?<?php echo rawurlencode($VERSION); ?>" sizes="180x180" />
 		<link rel="icon" type="image/png" href="img/favicon-32x32.png?<?php echo rawurlencode($VERSION); ?>" sizes="32x32" />

tst/ViewTest.php

@@ -60,6 +60,7 @@ class ViewTest extends PHPUnit_Framework_TestCase
         $page->assign('HTTPWARNING', true);
         $page->assign('HTTPSLINK', 'https://example.com/');
         $page->assign('COMPRESSION', 'zlib');
+        $page->assign('CSPHEADER', 'default-src \'none\'');
 
         $dir = dir(PATH . 'tpl');
         while (false !== ($file = $dir->read())) {