VULNERABILITY INTELLIGENCE
CVE-2023-23934
CVSS score2.6 LOW
EPSS probability0.51%
CISA KEVNot currently listed
Published2023-02-14
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
Description
Werkzeug is a comprehensive WSGI web application library. Browsers may allow "nameless" cookies that look like `=value` instead of `key=value`. A vulnerable browser may allow a compromised application on an adjacent subdomain to exploit this to set a cookie like `=__Host-test=bad` for another subdomain. Werkzeug prior to 2.2.3 will parse the cookie `=__Host-test=bad` as __Host-test=bad`. If a Werkzeug application is running next to a vulnerable or malicious subdomain which sets such a cookie using a vulnerable browser, the Werkzeug application will see the bad cookie value but the valid cookie key. The issue is fixed in Werkzeug 2.2.3.
Weakness classification
- CWE-20: Improper Input Validation
Primary references
- security-advisories@github.com — Patch
- security-advisories@github.com — Release Notes
- security-advisories@github.com — Vendor Advisory
- security-advisories@github.com
- security-advisories@github.com
- af854a3a-2127-422b-91ae-364da2661108 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Release Notes
- af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108