CVE-2023-34464 (published 2023-06-23T15:15Z)

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Starting in version 2.2.1 until versions 14.4.8, 14.10.5, and 15.1RC1 of org.xwiki.platform:xwiki-platform-web and any version prior to 14.4.8, 14.10.5, and 15.1.RC1 of org.xwiki.platform:xwiki-platform-web-templates, any user who can edit a document in a wiki like the user profile can create a stored cross-site scripting attack. The attack occurs by putting plain HTML code into that document and then tricking another user to visit that document with the `displaycontent` or `rendercontent` template and plain output syntax. If a user with programming rights is tricked into visiting such a URL, arbitrary actions be performed with this user's rights, impacting the confidentiality, integrity, and availability of the whole XWiki installation. This has been patched in XWiki 14.4.8, 14.10.5 and 15.1RC1 by setting the content type of the response to plain text when the output syntax is not an HTML syntax.

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/xwiki/xwiki-platform
commit_details: repo_url: https://github.com/xwiki/xwiki-platform
author: Michael Hamann
author_date: 2023-02-06 14:18:39+01:00
msg: XWIKI-20290: Set correct content type in rendercontent.vm

* Set the content type to text/plain when the output syntax is not HTML
* Add a page test
repository: repo_url: https://github.com/xwiki/xwiki-platform
repo_name: xwiki/xwiki-platform
description: The XWiki platform
repo_language: Java
owner: xwiki
file_changes: filename: rendercontent.vm
change_type: ModificationType.MODIFY
diff: @@ -33,7 +33,20 @@
   $services.progress.pushLevel(1)
 #end
 $services.progress.startStep('Compute the content to display')
-## Make sure we don't escape the content since we want HTML to be rendered
+## Set the content type to text/plain when the output syntax is not HTML to avoid that other content is interpreted
+## as HTML by the browser. This needs to be done before calling contentvars.vm as rendering the content can modify
+## the content type when the document, e.g., produces JSON.
+#if ($response.getContentType() != 'text/plain')
+  #set ($outputSyntax = $xwiki.getAvailableRendererSyntax($request.outputSyntax, $request.outputSyntaxVersion))
+  #if ($outputSyntax)
+    #set ($syntaxType = $outputSyntax.type.toIdString())
+    #if ($syntaxType != "xhtml" && $syntaxType != "html")
+      $response.setContentType('text/plain')
+    #end
+  #end
+#end
+## Make sure we don't escape the content since non-HTML output like JSON is produced by some documents when plain
+## output syntax is specified.
 #set ($noEscapeContent = true)
 #template("contentvars.vm")
 $services.progress.endStep()

programming_language: PowerShell
filename: DisplaycontentPageTest.java
change_type: ModificationType.ADD
diff: @@ -0,0 +1,131 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.web;
+
+import javax.inject.Inject;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.xwiki.job.script.ProgressScripService;
+import org.xwiki.model.reference.DocumentReference;
+import org.xwiki.rendering.syntax.Syntax;
+import org.xwiki.template.TemplateManager;
+import org.xwiki.template.script.TemplateScriptService;
+import org.xwiki.test.annotation.ComponentList;
+import org.xwiki.test.page.HTML50ComponentList;
+import org.xwiki.test.page.PageTest;
+import org.xwiki.test.page.XWikiSyntax21ComponentList;
+
+import com.xpn.xwiki.XWikiException;
+import com.xpn.xwiki.doc.XWikiDocument;
+import com.xpn.xwiki.web.XWikiServletResponseStub;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Tests the {@code displaycontent.vm} template.
+ *
+ * @version $Id$
+ */
+@HTML50ComponentList
+@XWikiSyntax21ComponentList
+@ComponentList({
+    TemplateScriptService.class,
+    ProgressScripService.class
+})
+class DisplaycontentPageTest extends PageTest
+{
+    private static final DocumentReference TEST_REFERENCE = new DocumentReference("xwiki", "space", "page");
+
+    private static final String TEMPLATE_NAME = "displaycontent.vm";
+
+    private static final String HTML_CONTENT_TYPE = "text/html; charset=utf-8";
+
+    private XWikiDocument document;
+
+    @Inject
+    private TemplateManager templateManager;
+
+    @BeforeEach
+    void setUp() throws XWikiException
+    {
+        this.document = new XWikiDocument(TEST_REFERENCE);
+        this.document.setSyntax(Syntax.XWIKI_2_1);
+        this.xwiki.saveDocument(this.document, this.context);
+        this.context.setDoc(this.document);
+
+        // Allow setting the content type in the response, so we can assert it later. The default is consistent with
+        // Utils#parseTemplate(String, boolean, XWikiContext).
+        this.response = new XWikiServletResponseStub()
+        {
+            private String contentType = HTML_CONTENT_TYPE;
+
+            @Override
+            public String getContentType()
+            {
+                return this.contentType;
+            }
+
+            @Override
+            public void setContentType(String type)
+            {
+                this.contentType = type;
+            }
+        };
+        this.context.setResponse(this.response);
+    }
+
+    @Test
+    void renderHTML() throws Exception
+    {
+        this.document.setContent("Hello World");
+        this.xwiki.saveDocument(this.document, this.context);
+
+        String result = this.templateManager.render(TEMPLATE_NAME).trim();
+        assertEquals("<p>Hello World</p>", result);
+        assertEquals(HTML_CONTENT_TYPE, this.response.getContentType());
+    }
+
+    @Test
+    void renderJSON() throws Exception
+    {
+        String json = "{\"hello\": \"world\"}";
+        this.document.setContent(json
+            + " {{velocity}}#set ($discard = $response.setContentType('application/json')){{/velocity}}");
+        this.xwiki.saveDocument(this.document, this.context);
+        this.request.put("outputSyntax", "plain");
+
+        String result = this.templateManager.render(TEMPLATE_NAME).trim();
+        assertEquals(json, result);
+        assertEquals("application/json", this.response.getContentType());
+    }
+
+    @Test
+    void renderPlain() throws Exception
+    {
+        this.document.setContent("<strong>Some HTML</strong>");
+        this.xwiki.saveDocument(this.document, this.context);
+        this.request.put("outputSyntax", "plain");
+
+        String result = this.templateManager.render(TEMPLATE_NAME).trim();
+        assertEquals(this.document.getContent(), result);
+        assertEquals("text/plain", this.response.getContentType());
+    }
+}

programming_language: Java