CVE-2020-4051 (published 2020-06-15T22:15Z)

In Dijit before versions 1.11.11, and greater than or equal to 1.12.0 and less than 1.12.9, and greater than or equal to 1.13.0 and less than 1.13.8, and greater than or equal to 1.14.0 and less than 1.14.7, and greater than or equal to 1.15.0 and less than 1.15.4, and greater than or equal to 1.16.0 and less than 1.16.3, there is a cross-site scripting vulnerability in the Editor's LinkDialog plugin. This has been fixed in 1.11.11, 1.12.9, 1.13.8, 1.14.7, 1.15.4, 1.16.3.

Severity: LOW
CVSS v2 base score: 3.5 (AV:N/AC:M/Au:S/C:N/I:P/A:N)
CVSS v3 base score: 5.4, MEDIUM (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N)

Weakness information:
cwe_id: CWE-79
cwe_name: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
description: The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
extended_description: 
            Cross-site scripting (XSS) vulnerabilities occur when:
            
               Untrusted data enters a web application, typically from a web request.
               The web application dynamically generates a web page that contains this untrusted data.
               During page generation, the application does not prevent the data from containing content that is executable by a web browser, such as JavaScript, HTML tags, HTML attributes, mouse events, Flash, ActiveX, etc.
               A victim visits the generated web page through a web browser, which contains malicious script that was injected using the untrusted data.
               Since the script comes from a web page that was sent by the web server, the victim's web browser executes the malicious script in the context of the web server's domain.
               This effectively violates the intention of the web browser's same-origin policy, which states that scripts in one domain should not be able to access resources or run code in a different domain.
            
            There are three main kinds of XSS:
            
               
                  Type 1: Reflected XSS (or Non-Persistent) - 
         			The server reads data directly from the HTTP request and reflects it back in the HTTP response. Reflected XSS exploits occur when an attacker causes a victim to supply dangerous content to a vulnerable web application, which is then reflected back to the victim and executed by the web browser. The most common mechanism for delivering malicious content is to include it as a parameter in a URL that is posted publicly or e-mailed directly to the victim. URLs constructed in this manner constitute the core of many phishing schemes, whereby an attacker convinces a victim to visit a URL that refers to a vulnerable site. After the site reflects the attacker's content back to the victim, the content is executed by the victim's browser.
               
                  Type 2: Stored XSS (or Persistent) - 
               The application stores dangerous data in a database, message forum, visitor log, or other trusted data store. At a later time, the dangerous data is subsequently read back into the application and included in dynamic content. From an attacker's perspective, the optimal place to inject malicious content is in an area that is displayed to either many users or particularly interesting users. Interesting users typically have elevated privileges in the application or interact with sensitive data that is valuable to the attacker. If one of these users executes malicious content, the attacker may be able to perform privileged operations on behalf of the user or gain access to sensitive data belonging to the user. For example, the attacker might inject XSS into a log message, which might not be handled properly when an administrator views the logs.
            
               
                  Type 0: DOM-Based XSS - 
               In DOM-based XSS, the client performs the injection of XSS into the page; in the other types, the server performs the injection. DOM-based XSS generally involves server-controlled, trusted script that is sent to the client, such as Javascript that performs sanity checks on a form before the user submits it. If the server-supplied script processes user-supplied data and then injects it back into the web page (such as with dynamic HTML), then DOM-based XSS is possible.
            
            
            Once the malicious script is injected, the attacker can perform a variety of malicious activities. The attacker could transfer private information, such as cookies that may include session information, from the victim's machine to the attacker. The attacker could send malicious requests to a web site on behalf of the victim, which could be especially dangerous to the site if the victim has administrator privileges to manage that site. Phishing attacks could be used to emulate trusted web sites and trick the victim into entering a password, allowing the attacker to compromise the victim's account on that web site. Finally, the script could exploit a vulnerability in the web browser itself possibly taking over the victim's machine, sometimes referred to as "drive-by hacking."
            In many cases, the attack can be launched without the victim even being aware of it. Even with careful users, attackers frequently use a variety of methods to encode the malicious portion of the attack, such as URL encoding or Unicode, so the request looks less suspicious.
         
         

Fix information:
repo_url: https://github.com/dojo/dijit
commit_details: repo_url: https://github.com/dojo/dijit
author: Mangala Sadhu Sangeet Singh Khalsa
author_date: 2020-06-13 05:02:38-07:00
msg: Merge pull request from GHSA-cxjc-r2fp-7mq6

* Add config option `allowUnsafeHtml`: default is `false` which results in
  `<` being replaced with `&lt;`
* Add config option `linkFilter`: can be a function or array of filter pairs
  to control exactly what filtering is applied

This update should minimally affect production applications:

* The behavior of existing links with HTML content will be unchanged
* Existing links that are edited and saved will be filtered (this is only if
  the link is edited, other content within the editor can be edited without
  affecting the link)
* Newly created links will be filtered by default
* For production code to continue working as-is with new data the application
  code will have to be updated to specify `true` for the `LinkDialog` plugin's
  `allowUnsafeHtml` option
(cherry picked from commit 7d9d4927a26a246719e153c1fad557b9a956eb60)
repository: repo_url: https://github.com/dojo/dijit
repo_name: dojo/dijit
description: Dojo 1 - UI library
repo_language: HTML
owner: dojo
file_changes: filename: LinkDialog.js
change_type: ModificationType.MODIFY
diff: @@ -1,5 +1,6 @@
 define([
 	"require",
+	"dojo/_base/array",
 	"dojo/_base/declare", // declare
 	"dojo/dom-attr", // domAttr.get
 	"dojo/keys", // keys.ENTER
@@ -11,7 +12,7 @@ define([
 	"../_Plugin",
 	"../../form/DropDownButton",
 	"../range"
-], function(require, declare, domAttr, keys, lang, on, has, query, string,
+], function(require, array, declare, domAttr, keys, lang, on, has, query, string,
 	_Plugin, DropDownButton, rangeapi){
 
 	// module:
@@ -26,6 +27,21 @@ define([
 		//
 		//		- createLink
 
+		// allowUnsafeHtml: boolean
+		//		If false (default), the link description will be filtered to prevent HTML content.
+		//		If true no filtering is done, allowing for HTML content within the link element.
+		//		The filter can be specified with the 'linkFilter' option.
+		allowUnsafeHtml: false,
+
+		// linkFilter: function or array of replacement pairs
+		//		If 'allowUnsafeHtml' is false then this filter will be applied to the link Description value.
+		//		function: the function will be invoked with the string value of the Description field and its
+		//			return value will be used
+		//		array: each array item should be an array of two values to pass to String#replace
+		linkFilter: [
+			[/</g, "&lt;"]
+		],
+
 		// Override _Plugin.buttonClass.   This plugin is controlled by a DropDownButton
 		// (which triggers a TooltipDialog).
 		buttonClass: DropDownButton,
@@ -252,6 +268,16 @@ define([
 			if(args && args.urlInput){
 				args.urlInput = args.urlInput.replace(/"/g, "&quot;");
 			}
+			if(!this.allowUnsafeHtml && args && args.textInput){
+				if(typeof this.linkFilter === 'function'){
+					args.textInput = this.linkFilter(args.textInput);
+				}
+				else{
+					array.forEach(this.linkFilter, function (currentFilter) {
+						args.textInput = args.textInput.replace(currentFilter[0], currentFilter[1]);
+					});
+				}
+			}
 			return args;
 		},
 
@@ -629,8 +655,15 @@ define([
 	});
 
 	// Register these plugins
-	_Plugin.registry["createLink"] = function(){
-		return new LinkDialog({command: "createLink"});
+	_Plugin.registry["createLink"] = function(args){
+		var pluginOptions = {
+			command: "createLink",
+			allowUnsafeHtml: ("allowUnsafeHtml" in args) ? args.allowUnsafeHtml : false
+		};
+		if("linkFilter" in args){
+			pluginOptions.linkFilter = args.linkFilter;
+		}
+		return new LinkDialog(pluginOptions);
 	};
 	_Plugin.registry["insertImage"] = function(){
 		return new ImgLinkDialog({command: "insertImage"});

programming_language: JavaScript
filename: test_LinkDialog.html
change_type: ModificationType.MODIFY
diff: @@ -7,6 +7,10 @@
 	<script type="text/javascript" src="../boilerplate.js"></script>
 
 	<script type="text/javascript">
+		function filterLink () {
+			return 'Filtered Value';
+		}
+
 		require([
 			"dojo/parser",
 			"dijit/Editor",
@@ -36,6 +40,22 @@
 		</div>
 	</div>
 
+	<p>Editor with <code>allowUnsafeHtml</code> set to <code>true</code></p>
+	<div style="border: 1px dotted black;">
+		<div id="editorUnsafe" data-dojo-type="dijit/Editor" data-dojo-props='"aria-label":"editor",extraPlugins:[{name: "createLink", allowUnsafeHtml: true}, "insertImage", "viewSource"]'>
+			<p>This editor will allow unrestricted HTML in the Description field of links</p>
+			<br>
+		</div>
+	</div>
+
+	<p>Editor with custom <code>linkFilter</code> function</p>
+	<div style="border: 1px dotted black;">
+		<div id="editorLinkFilter" data-dojo-type="dijit/Editor" data-dojo-props='"aria-label":"editor",extraPlugins:[{name: "createLink", linkFilter: filterLink}, "insertImage", "viewSource"]'>
+			<p>Links created in this editor will always have a description of "Filtered Value", which is the value returned by the custom <code>linkFilter</code> function.</p>
+			<br>
+		</div>
+	</div>
+
 	<p>RTL Editor:</p>
 	<div style="border: 1px dotted black;">
 		<div id="reditor" data-dojo-type="dijit/Editor" dir="rtl" data-dojo-props='"aria-label":"reditor",extraPlugins:["createLink", "insertImage"]'>

programming_language: HTML