XWiki missing authorization when accessing the wiki level attachments list and metadata via REST API

Impact

Anyone can access the metadata of any attachment in the wiki using the wiki attachment REST endpoint. It's not filtering the result depending on current user rights, a not authenticated user could exploit this even in a totally private wiki.

To reproduce:

• remove view from guest on the whole wiki
• logout
• access http://127.0.0.1:8080/xwiki/rest/wikis/xwiki/spaces/Sandbox/pages/WebHome/attachments

You get a list of attachments, while the expected result should be an empty list.

Patches

This vulnerability has been fixed in XWiki 14.10.22, 15.10.12, 16.7.0-rc-1 and 16.4.3.

Workarounds

We're not aware of any workaround except upgrading.

References

• https://jira.xwiki.org/browse/XWIKI-22424
• https://jira.xwiki.org/browse/XWIKI-22427
• https://github.com/xwiki/xwiki-platform/commit/a43e933ddeda17dad1772396e1757998260e9342#diff-0

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

Attribution

Issue reported by Lukas Monert.