Wrkzeug's incorrect parsing of nameless cookies leads to __Host- cookies bypass (pallets werkzeug)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.51 % · percentile 43 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-20 — Improper Input Validation
References
- https://github.com/pallets/werkzeug/security/advisories/GHSA-px8h-6qxv-m22q
- https://github.com/pallets/werkzeug/commit/cf275f42acad1b5950c50ffe8ef58fe62cdce028
- https://github.com/pallets/werkzeug/releases/tag/2.2.3
- https://www.debian.org/security/2023/dsa-5470
- https://security.netapp.com/advisory/ntap-20230818-0003/
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 2.6 | CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N | GitHub_M |
| CVSS 3.1 | LOW 2.6 | CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | LOW 3.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-px8h-6qxv-m22q — Incorrect parsing of nameless cookies leads to __Host- cookies bypass
- PYSEC-2023-57 — Werkzeug is a comprehensive WSGI web application library. Browsers may allow "nameless" cookies that look like `=value` instead of `key=value`. A vulnerable bro
European references
- ENISA EUVD · EUVD-2023-0281
- GCVE · GCVE-0-2023-23934
CERT-FR advisories
- CERTFR-2025-AVI-0546 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0309 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2024-AVI-0903 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2024-AVI-0366 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2024-AVI-0119 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2023-AVI-0791 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2023-AVI-0627 — Multiples vulnérabilités dans IBM Spectrum · cert.ssi.gouv.fr
- CERTFR-2023-AVI-0484 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2023-AVI-0427 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:palletsprojects:werkzeug:*:*:*:*:*:*:*:*< 2.2.3
Affected products
| Product | Versions |
|---|---|
| pallets · werkzeug | affected < 2.2.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |