GHSA-gx4f-976g-7g6v XWiki Platform vulnerable to data leak via Improper Restriction of XML External Entity Reference

• Maven org.xwiki.platform:xwiki-platform-xar-model: >= 1.1-milestone-3, < 13.10.11 → fixed in 13.10.11 • Maven org.xwiki.platform:xwiki-platform-xar-model: >= 14.0, < 14.4.7 → fixed in 14.4.7 • Maven org.xwiki.platform:xwiki-platform-xar-model: >= 14.5, < 14.10-rc-1 → fixed in 14.10-rc-1

Impact Any user with edit rights on a document can trigger a XAR import on a forged XAR file, leading to the ability to display the content of any file on the XWiki server host. Example to reproduce: • Create a forget XAR file and inside it, have the following `package.xml` content: ```xml ]> &xxe; &xxe; Helper pages for creating and listing Class/Template/Sheets XWiki.Admin ... ``` • Upload it onto a wiki page (e.g. `XXE`) as an attachment (e.g. `test.xar`). • Call the page using `http://localhost:8080/xwiki/bin/view/Main/XXE?sheet=XWiki.AdminImportSheet&file=test.xar` You'll then notice that the displayed UI contains the content of the `/etc/passwd` file. Patches The vulnerability has been patched in XWiki 13.10.11, 14.4.7 and 14.10-rc-1. Workarounds You'd need to get XWiki Platform sources and apply the changes from https://github.com/xwiki/xwiki-platform/commit/e3527b98fdd8dc8179c24dc55e662b2c55199434 to the `XarPackage` java class and then copy the modified version to your `WEB-INF/classes` directory (or rebuild the `xwiki-platform-xar-model` maven module and replace the one found in `WEB-INF/lib/`). References • https://github.com/xwiki/xwiki-platform/commit/e3527b98fdd8dc8179c24dc55e662b2c55199434 • https://jira.xwiki.org/browse/XWIKI-20320 For more information If you have any questions or comments about this advisory: • Open an issue in Jira XWiki.org • Email us at Security Mailing List