CVE-2024-28179: Jupyter Server Proxy's Websocket Proxying does not require authentication

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 1.0%, percentile 63: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 63% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes jupyter-server-proxy (PyPI) >= 4.0.0, < 4.1.1, fixed in 4.1.1; jupyter-server-proxy (PyPI) < 3.2.3, fixed in 3.2.3. Check your lockfile, including transitive dependencies.

What it is

Jupyter Server Proxy allows users to run arbitrary external processes alongside their Jupyter notebook servers and provides authenticated web access. Prior to versions 3.2.3 and 4.1.1, Jupyter Server Proxy did not check user authentication appropriately when proxying websockets, allowing unauthenticated access to anyone who had network access to the Jupyter server endpoint. This vulnerability can allow unauthenticated remote access to any websocket endpoint set up to be accessible via Jupyter Server Proxy. In many cases, this leads to remote unauthenticated arbitrary code execution, due to how affected instances use websockets. The websocket endpoints exposed by jupyterserver itself is not affected. Projects that do not rely on websockets are also not affected. Versions 3.2.3 and 4.1.1 contain a fix for this issue.

From the GitHub advisory

Summary

jupyter-server-proxy is used to expose ports local to a Jupyter server listening to web traffic to the Jupyter server's authenticated users by proxying web requests and websockets. Dependent packages (partial list) also use jupyter-server-proxy to expose other popular interactive applications (such as RStudio, Linux Desktop via VNC, Code Server, Panel, etc) along with the Jupyter server. This feature is commonly used in hosted environments (such as a JupyterHub) to expose non-Jupyter interactive frontends or APIs to the user.

jupyter-server-proxy did not check user authentication appropriately when proxying websockets, allowing unauthenticated access to anyone who had network access to the Jupyter server endpoint.

Impact

This vulnerability can allow unauthenticated remote access to any websocket endpoint set up to be accessible via jupyter-server-proxy. In many cases (such as when exposing RStudio via jupyter-rsession-proxy or a remote Linux Desktop / VNC via jupyter-remote-desktop-proxy), this leads to remote unauthenticated arbitrary code execution, due to how they use websockets. The websocket endpoints exposed by jupyterserver itself is not affected. Projects that do not rely on websockets are also not affected.

Weakness type: CWE-306.

Product: jupyter-server-proxy (PyPI) · Assigned by: GitHub_M · Published: 2024-03-20

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: high (needs special conditions)
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 1.03% probability of exploitation activity in the next 30 days; percentile 63.

Timeline

• 2024-03-20 — CVE record published by GitHub_M
• 2024-03-20 — GitHub-reviewed advisory GHSA-w3vc-fx9p-wp4v published (critical)
• 2024-08-02 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-w3vc-fx9p-wp4v github.com
2. CVE.org record CVE-2024-28179 cve.org
3. NVD entry CVE-2024-28179 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com

Critical PyPI advisories · Today’s Security Digest