CVE-2021-41247: incomplete logout in JupyterHub
Impact
Users of JupyterLab with JupyterHub who have multiple JupyterLab tabs open in the same browser session, may see incomplete logout from the single-user server, as fresh credentials (for the single-user server only, not the Hub) reinstated after logout, if another active JupyterLab session is open while the logout takes place.
Patches
Upgrade to JupyterHub 1.5. For distributed deployments, it is jupyterhub in the user environment that needs patching. There are no patches necessary in the Hub environment.
Workarounds
The only workaround is to make sure that only one JupyterLab tab is open when you log out.
Other sources
JupyterHub is an open source multi-user server for Jupyter notebooks. In affected versions users who have multiple JupyterLab tabs open in the same browser session, may see incomplete logout from the single-user server, as fresh credentials (for the single-user server only, not the Hub) reinstated after logout, if another active JupyterLab session is open while the logout takes place. Upgrade to JupyterHub 1.5. For distributed deployments, it is jupyterhub in the user environment that needs patching. There are no patches necessary in the Hub environment. The only workaround is to make sure that only one JupyterLab tab is open when you log out.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2021-41247?
CVE-2021-41247 is a vulnerability in JupyterHub that can result in incomplete logout from the single-user server.
What is the severity of CVE-2021-41247?
CVE-2021-41247 has a severity rating of 7.5 (high).
How does CVE-2021-41247 affect JupyterHub?
CVE-2021-41247 affects JupyterHub versions from 1.0.0 to 1.5.0.
How can I fix CVE-2021-41247?
To fix CVE-2021-41247, it is recommended to update JupyterHub to a version beyond 1.5.0.
Where can I find more information about CVE-2021-41247?
More information about CVE-2021-41247 can be found in the following references: [link1](https://github.com/jupyterhub/jupyterhub/commit/5ac9e7f73a6e1020ffddc40321fc53336829fe27), [link2](https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-cw7p-q79f-m2v7).