CVE-2021-32798

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

### Impact Untrusted notebook can execute code on load. This is a remote code execution, but requires user action to open a notebook. ### Patches 5.7.11, 6.4.1 ### References [OWASP Page on Injection Prevention](https://cheatsheetseries.owasp.org/cheatsheets/Injection_Prevention_Cheat_Sheet.html#injection-prevention-rules) ### 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 ### Example: A notebook with the following content in a cell and it would display an alert when opened for the first time in Notebook (in an untrusted state): ``` { "cell_type": "code", "execution_count": 0, "metadata": {}, "outputs": [ { "data": { "text/html": [ "<select><iframe></select><img src=x: onerror=alert('xss')>\n"], "text/plain": [] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "" ] } ````

Jupyter notebook, es un entorno de cuaderno basado en la web para la computación interactiva. En las versiones afectadas, el cuaderno no fiable puede ejecutar código al cargarlo. Jupyter Notebook usa una versión obsoleta de Google Caja para sanear las entradas del usuario. Una omisión pública de Caja puede ser usado para desencadenar un ataque de tipo XSS cuando una víctima abre un documento ipynb malicioso en Jupyter Notebook. El ataque de tipo XSS permite a un atacante ejecutar código arbitrario en el ordenador de la víctima usando las API de Jupyter