Jupyter Server open redirect vulnerability

Impact

_What kind of vulnerability is it? Who is impacted?_

Open redirect vulnerability - a maliciously crafted link to a jupyter server could redirect the browser to a different website.

All jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may *appear* safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8.

Patches

_Has the problem been patched? What versions should users upgrade to?_

Patched in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix:

`

jupyter server --ServerApp.base_url=/jupyter/

`

References

[OWASP page on open redirects](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html)

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](mailto:security@ipython.org).

Credit: Yaniv Nizry from CxSCA group at Checkmarx