GHSA-gj55-2xf9-67rq HTML injection in JupyterLite leading to DOM Clobbering

Not scored Published 6 Sep 2024

Attackers can execute arbitrary code and access data via DOM clobbering in JupyterLite when users open malicious notebooks or markdown files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is GHSA-gj55-2xf9-67rq?

GHSA-gj55-2xf9-67rq is a cross-site scripting vulnerability in jupyterlite-core, published on 6 Sep 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

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 accessible from JupyterLite and perform arbitrary actions in JupyterLite environment.

Patches

JupyterLite 0.4.1 was 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 populate the disabledExtensions key in jupyter-config-data stanza of jupyter-lite.json as documented on https://jupyterlite.readthedocs.io/en/stable/howto/configure/config_files.html#jupyter-lite-json

{
  &#34;jupyter-lite-schema-version&#34;: 0,
  &#34;jupyter-config-data&#34;: {
    &#34;appName&#34;: &#34;My JupyterLite App&#34;,
    &#34;disabledExtensions&#34;: [
      &#34;@jupyterlab/markdownviewer-extension:plugin&#34;,
      &#34;@jupyterlab/mathjax-extension:plugin&#34;,
      &#34;@jupyterlab/mathjax2-extension:plugin&#34;
    ]
  }
}

To confirm that the plugins were disabled manual inspection of the built page is required.

References

Upstream advisory: https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-9q39-rmj3-p4r2

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).

Which versions are affected by GHSA-gj55-2xf9-67rq?

2 open source packages ship an affected version, including jupyterlite-core.

Package	Affected	Fixed in
`jupyterlite-core` PyPI	All versions	`0.4.1`
`jupyterlite-core` PyPI	All versions	`0.4.1`

How do I fix GHSA-gj55-2xf9-67rq?

Upgrade jupyterlite-core to 0.4.1 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is GHSA-gj55-2xf9-67rq being exploited?

There is no known exploitation of GHSA-gj55-2xf9-67rq in the wild and no public exploit code.