Skip to content

Privilege escalation (PR) from account through FlamingoThemesCode.WebHomeSheet

Critical
manuelleduc published GHSA-vrr8-fp7c-7qgp Apr 12, 2023

Package

maven org.xwiki.platform:xwiki-platform-flamingo-theme-ui (Maven)

Affected versions

>= 12.10.1, >= 12.6.6, >= 13.0

Patched versions

13.10.11, 14.4.7, 14.10

Description

Impact

Any user with the right to add an object on a page 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 the styles properties FlamingoThemesCode.WebHome. This page is installed by default.

Reproduction Steps

Steps to reproduce:

  • As a user without script or programming rights, edit your user profile with the object editor (enable advanced mode if necessary to get access) and add an object of type "Theme Class" of "FlamingoThemesCode". In the field "body-bg" (all other fields should work, too) add the following text:

{{/html}} {{async async="true" cached="false" context="doc.reference"}}{{groovy}}println("Hello " + "from groovy!"){{/groovy}}{{/async}}

  • Click "Save & View"
  • Open /xwiki/bin/view/FlamingoThemesCode/WebHomeSheet where is the URL of your XWiki installation

Expected result:

The list of color themes either doesn't include the user's profile or displays a regular preview.

Actual result:

The user's profile is listed as color theme but instead of the little preview the message

Failed to execute the [html] macro. Cause: [When using HTML content inline, you can only use inline HTML content. Block HTML content (such as tables) cannot be displayed. Try leaving an empty line before and after the macro.]. Click on this message for details.
Hello from groovy!">

is displayed. This shows that a Groovy macro with content created by the user has been executed and thus demonstrates a privilege escalation from simple user account to programming rights.

Patches

The vulnerability has been patched in XWiki 13.10.11, 14.4.7 and 14.10.

Workarounds

The issue can be fixed by applying this patch on FlamingoThemesCode.WebHomeSheet.

References

For more information

If you have any questions or comments about this advisory:

Severity

Critical
9.9
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

CVE ID

CVE-2023-30537

Weaknesses