Headline
CVE-2023-40170: cross-site inclusion (XSSI) of files
jupyter-server is the backend for Jupyter web applications. Improper cross-site credential checks on /files/ URLs could allow exposure of certain file contents, or accessing files when opening untrusted files via "Open image in new tab". This issue has been addressed in commit 87a49272728 which has been included in release 2.7.2. Users are advised to upgrade. Users unable to upgrade may use the lower performance --ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler, which implements the correct checks.
Impact
Improper cross-site credential checks on /files/ URLs could allow exposure of certain file contents, or accessing files when opening untrusted files via "Open image in new tab".
Patches
Jupyter Server 2.7.1
Workarounds
Use lower performance --ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler, which implements the correct checks.
References
Upstream patch for CVE-2019-9644 was not applied completely, leaving part of the vulnerability open.
Vulnerability reported by Tim Coen via the bug bounty program sponsored by the European Commission and hosted on the Intigriti platform.
Related news
### Impact Improper cross-site credential checks on `/files/` URLs could allow exposure of certain file contents, or accessing files when opening untrusted files via "Open image in new tab". ### Patches Jupyter Server 2.7.2 ### Workarounds Use lower performance `--ContentsManager.files_handler_class=jupyter_server.files.handlers.FilesHandler`, which implements the correct checks. ### References Upstream patch for CVE-2019-9644 was not applied completely, leaving part of the vulnerability open. Vulnerability reported by Tim Coen via the [bug bounty program](https://app.intigriti.com/programs/jupyter/jupyter/detail) [sponsored by the European Commission](https://commission.europa.eu/news/european-commissions-open-source-programme-office-starts-bug-bounties-2022-01-19_en) and hosted on the [Intigriti platform](https://www.intigriti.com/).
Ubuntu Security Notice 5585-1 - It was discovered that Jupyter Notebook incorrectly handled certain notebooks. An attacker could possibly use this issue of lack of Content Security Policy in Nbconvert to perform cross-site scripting attacks on the notebook server. This issue only affected Ubuntu 18.04 LTS. It was discovered that Jupyter Notebook incorrectly handled certain SVG documents. An attacker could possibly use this issue to perform cross-site scripting attacks. This issue only affected Ubuntu 18.04 LTS.