CVE-2021-41247 : Vulnerability Insights and Analysis
Learn about CVE-2021-41247 affecting JupyterHub, causing incomplete logouts and reinstatement of credentials. Upgrade to version 1.5 for mitigation. Find out more here.
JupyterHub is an open source multi-user server for Jupyter notebooks. In affected versions, users may experience incomplete logout, allowing fresh credentials to be reinstated under certain conditions.
Understanding CVE-2021-41247
JupyterHub vulnerability exposing users to incomplete logout sessions.
What is CVE-2021-41247?
- Users with multiple JupyterLab tabs open may face incomplete logout on the single-user server.
- Fresh credentials may be reinstated post-logout if another active JupyterLab session is open.
- Patching to version 1.5 of JupyterHub is recommended.
The Impact of CVE-2021-41247
- CVSS v3.1 Base Score: 3.5 (Low)
- Attack Vector: Network
- Attack Complexity: Low
- User Interaction: Required
- Confidentiality Impact: Low
- Integrity Impact: None
- Availability Impact: None
Technical Details of CVE-2021-41247
Details of the vulnerability within JupyterHub.
Vulnerability Description
- Insufficient logout causing the reissuance of credentials in specific browser session scenarios.
Affected Systems and Versions
- Affected Versions: >= 1.0.0, < 1.5.0 (pip), < 1.2.0 (helm)
Exploitation Mechanism
- Vulnerability triggered by having multiple JupyterLab tabs open during log out.
Mitigation and Prevention
Steps to mitigate the incomplete logout issue in JupyterHub.
Immediate Steps to Take
- Upgrade to JupyterHub version 1.5 to fix the incomplete logout.
- Ensure only one JupyterLab tab is open during log out.
Long-Term Security Practices
- Educate users on the risks of multiple open tabs during sensitive operations.
- Implement browser session management best practices to avoid incomplete logout scenarios.
Patching and Updates
- Apply patches provided by JupyterHub to address the incomplete logout issue.