XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user who can view `Invitation.WebHome` can execute arbitrary script macros including Groovy and Python macros that allow remote code execution including unrestricted read and write access to all wiki contents. This vulnerability has been patched on XWiki 14.4.8, 15.2-rc-1, and 14.10.6. Users are advised to upgrade. Users unable to upgrade may manually apply the patch on `Invitation.InvitationCommon` and `Invitation.InvitationConfig`, but there are otherwise no known workarounds for this vulnerability.

Affected: Maven: org.xwiki.platform:xwiki-platform-invitation-ui

### Impact Any user who can view `Invitation.WebHome` can execute arbitrary script macros including Groovy and Python macros that allow remote code execution including unrestricted read and write access to all wiki contents. This can be reproduced with the following steps:

1. Open the invitation application (Invitation.WebHome). 1. Set the subject to `{{cache}}{{groovy}}new File("/tmp/exploit.txt").withWriter { out -> out.println("Attacked from invitation!"); }{{/groovy}}{{/cache}}` 1. Click "Preview"

### Patches The vulnerability has been patched on XWiki 14.4.8, 15.2-rc-1, and 14.10.6.

### Workarounds The vulnerability can be patched manually by applying the [patch](https://github.com/xwiki/xwiki-platform/commit/ff1d8a1790c6ee534c6a4478360a06efeb2d3591) on `Invitation.InvitationCommon` and `Invitation.InvitationConfig`.

### References - https://jira.xwiki.org/browse/XWIKI-20421 - https://github.com/xwiki/xwiki-platform/commit/ff1d8a1790c6ee534c6a4478360a06efeb2d3591

### For more information

If you have any questions or comments about this advisory: * Open an issue in [Jira XWiki.org](https://jira.xwiki.org/) * Email us at [Security Mailing List](mailto:security@xwiki.org)