Scope of workflow operations is not validated

Description

Impact

A missing scope validation allowed users to create workflows which are designed to be only available for administrators. Some workflows are designed to be RCE by invoking defined scripts, in order to generate PDFs, invoking webhooks or running scripts on the server. Due to this combination depending on the available apps the issue can result in a RCE at the end.

Patches

It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4
It is recommended that the Nextcloud Enterprise Server is upgraded to 20.0.14.12 or 21.0.9.10 or 22.2.10.10 or 23.0.12.5 or 24.0.10 or 25.0.4
It is recommended that the Nextcloud Enterprise Server 18 or Nextcloud Enterprise Server 19 is manually patched.

Workarounds

• Disable app workflow_scripts and workflow_pdf_converter

References

• HackerOne

For more information

If you have any questions or comments about this advisory:

• Create a post in nextcloud/security-advisories
• Customers: Open a support ticket at support.nextcloud.com