Description (CNA)
Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| jupyter-server / jupyter_server | affected <= 2.17.0 |
CWE
CWE-777
References
- https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-24qx-w28j-9m6p
- https://github.com/jupyter-server/jupyter_server/pull/603
- https://github.com/jupyter-server/jupyter_server/commit/057869a327c46730afede3eab0ca2d2e3e74acea
- https://github.com/jupyter-server/jupyter_server/commit/49b34392feaa97735b3b777e3baf8f22f2a14ed8
ADP enrichment
No English description supplied.
No references supplied.
A flaw was found in Jupyter Server. The Origin header validation, which uses Python's `re.match()` function, does not correctly validate incoming origins against allowed patterns. This allows a remote attacker to bypass Cross-Origin Resource Sharing (CORS) restrictions by crafting a malicious domain that partially matches a trusted one. Consequently, the attacker can make unauthorized cross-origin requests to the Jupyter Server API from an untrusted site, potentially leading to sensitive information disclosure or other unauthorized actions.