CVE-2023-27479 (published 2023-03-07T19:15Z)

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. In affected versions any user with view rights can execute arbitrary Groovy, Python or Velocity code in XWiki leading to full access to the XWiki installation. The root cause is improper escaping of UIX parameters. A proof of concept exploit is to log in, add an `XWiki.UIExtensionClass` xobject to the user profile page, with an Extension Parameters content containing `label={{/html}} {{async async="true" cached="false" context="doc.reference"}}{{groovy}}println("Hello " + "from groovy!"){{/groovy}}{{/async}}`. Then, navigating to `PanelsCode.ApplicationsPanelConfigurationSheet` (i.e., `<xwiki-host>/xwiki/bin/view/PanelsCode/ApplicationsPanelConfigurationSheet` where `<xwiki-host>` is the URL of your XWiki installation) should not execute the Groovy script. If it does, you will see `Hello from groovy!` displayed on the screen. This vulnerability has been patched in XWiki 13.10.11, 14.4.7 and 14.10-rc-1. Users are advised to upgrade. For users unable to upgrade the issue can be fixed by editing the `PanelsCode.ApplicationsPanelConfigurationSheet` wiki page and making the same modifications  as shown in commit `6de5442f3c`.

CVSS v3 base score: 9.9, CRITICAL (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-74
cwe_name: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
description: The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
extended_description: Software or other automated logic has certain assumptions about what constitutes data and control respectively. It is the lack of verification of these assumptions for user-controlled input that leads to injection problems. Injection problems encompass a wide variety of issues -- all mitigated in very different ways and usually attempted in order to alter the control flow of the process. For this reason, the most effective way to discuss these weaknesses is to note the distinct features that classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed.
         

Fix information:
repo_url: https://github.com/xwiki/xwiki-platform
commit_details: repo_url: https://github.com/xwiki/xwiki-platform
author: Vincent Massol
author_date: 2022-10-27 14:50:01+02:00
msg: XWIKI-20294: Improve escaping in Applications Panel Configuration sheet
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: ApplicationsPanelConfigurationSheet.xml
change_type: ModificationType.MODIFY
diff: @@ -84,14 +84,15 @@
           &lt;ul class="nav nav-pills applicationsPanel"&gt;
             #foreach($app in $apps)
               #set($params = $app.uix.getParameters())
-              #if("$!params.icon" != '' &amp;&amp; "$!params.label" != '' &amp;&amp; "$!params.target" != '' &amp;&amp; $xwiki.hasAccessLevel('view', $xcontext.user, $params.target))
-                #if ($params.icon.startsWith('icon:'))
-                  #set($icon = $services.icon.renderHTML($params.icon.substring(5)))
+              #set($normalizedIcon = $stringtool.substringBefore($!params.icon, ' '))
+              #if("$!normalizedIcon" != '' &amp;&amp; "$!params.label" != '' &amp;&amp; "$!params.target" != '' &amp;&amp; $xwiki.hasAccessLevel('view', $xcontext.user, $params.target))
+                #if ($normalizedIcon.startsWith('icon:'))
+                  #set($icon = $services.icon.renderHTML($normalizedIcon.substring(5)))
                 #else
-                  #set($icon = $services.rendering.render($services.rendering.parse("image:${params.icon}", 'xwiki/2.1'), 'xhtml/1.0'))
+                  #set($icon = $services.rendering.render($services.rendering.parse("image:${normalizedIcon}", 'xwiki/2.1'), 'xhtml/1.0'))
                 #end
-                &lt;li class="draggableApp" id="$app.uix.id"&gt;
-                  &lt;a&gt;&lt;span class="application-img"&gt;$icon &lt;/span&gt; &lt;span class="application-label"&gt;$params.label&lt;/a&gt;
+                &lt;li class="draggableApp" id="$escapetool.xml($app.uix.id)"&gt;
+                  &lt;a&gt;&lt;span class="application-img"&gt;$icon &lt;/span&gt; &lt;span class="application-label"&gt;$escapetool.xml($params.label)&lt;/a&gt;
                 &lt;/li&gt;
               #end
             #end

programming_language: PHP