Impact What kind of vulnerability is it? Who is impacted? We’d like to disclose an arbitrary code execution vulnerability in jupytercore that stems from jupytercore executing untrusted files in the current working directory. This vulnerability allows one user to run code as another.

Patches Has the problem been patched? What versions should users upgrade to? Users should upgrade to jupytercore>=4.11.2.

Workarounds Is there a way for users to fix or remediate the vulnerability without upgrading? No

References Are there any links users can visit to find out more? Similar advisory in IPython

Impact

Untrusted notebook can execute code on load. This is a remote code execution, but requires user action to open a notebook.

Patches

Patched in the following versions: 3.1.4, 3.0.17, 2.3.2, 2.2.10, 1.2.21.

References

OWASP Page on Restricting Form Submissions

For more information

If you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list security@ipython.org.

Credit: Guillaume Jeanne from Google

Impact

The vulnerability depends on user interaction by opening a malicious notebook with Markdown cells, or Markdown file using JupyterLab preview feature.

A malicious user can access any data that the attacked user has access to as well as perform arbitrary requests acting as the attacked user.

Patches

JupyterLab v3.6.8, v4.2.5 and Jupyter Notebook v7.2.2 were patched.

Workarounds

There is no workaround for the underlying DOM Clobbering susceptibility. However, select plugins can be disabled on deployments which cannot update in a timely fashion to minimise the risk. These are: - @jupyterlab/mathjax-extension:plugin - users will loose ability to preview mathematical equations - @jupyterlab/markdownviewer-extension:plugin - users will loose ability to open Markdown previews - @jupyterlab/mathjax2-extension:plugin (if installed with optional jupyterlab-mathjax2 package) - an older version of the mathjax plugin for JupyterLab 4.x

To disable these extensions run:

bash jupyter labextension disable @jupyterlab/markdownviewer-extension:plugin jupyter labextension disable @jupyterlab/mathjax-extension:plugin jupyter labextension disable @jupyterlab/mathjax2-extension:plugin

To confirm that the plugins were disabled run:

bash jupyter labextension list

References

None

Notes

This change has a potential to break rendering of some markdown. There is a setting in Sanitizer which allows to revert to the previous sanitizer settings (allowNamedProperties).