CVE-2024-28233

Cross site scripting (XSS) in JupyterHub via Self-XSS leveraged by Cookie Tossing

Affected configurations:

• Single-origin JupyterHub deployments
• JupyterHub deployments with user-controlled applications running on subdomains or peer subdomains of either the Hub or a single-user server.

By tricking a user into visiting a malicious subdomain, the attacker can achieve an XSS directly affecting the former's session. More precisely, in the context of JupyterHub, this XSS could achieve the following:

• Full access to JupyterHub API and user's single-user server, e.g.
  • Create and exfiltrate an API Token
  • Exfiltrate all files hosted on the user's single-user server: notebooks, images, etc.
  • Install malicious extensions. They can be used as a backdoor to silently regain access to victim's session anytime.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2024-28233 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.1.0); upgrading removes the vulnerable code path.

Kodem intelligence

To prevent cookie-tossing:

• Upgrade to JupyterHub 4.1 (both hub and user environment)
• enable per-user domains via c.JupyterHub.subdomain_host = "https://mydomain.example.org"
• set c.JupyterHub.cookie_host_prefix_enabled = True to enable domain-locked cookies

or, if available (applies to earlier JupyterHub versions):

• deploy jupyterhub on its own domain, not shared with any other services
• enable per-user domains via c.JupyterHub.subdomain_host = "https://mydomain.example.org"

1. What is CVE-2024-28233? CVE-2024-28233 is a high-severity cross-site scripting (XSS) vulnerability in jupyterhub (pip), affecting versions < 4.1.0. It is fixed in 4.1.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2024-28233? CVE-2024-28233 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of jupyterhub are affected by CVE-2024-28233? jupyterhub (pip) versions < 4.1.0 is affected.
4. Is there a fix for CVE-2024-28233? Yes. CVE-2024-28233 is fixed in 4.1.0. Upgrade to this version or later.
5. Is CVE-2024-28233 exploitable, and should I be worried? Whether CVE-2024-28233 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-28233 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-28233? Upgrade jupyterhub to 4.1.0 or later.