CVE-2023-23934: Wrkzeug's incorrect parsing of nameless cookies leads to __Host- cookies bypass
First published: Tue Feb 14 2023(Updated: )
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 <= 2.2.2 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.
Credit: security-advisories@github.com security-advisories@github.com security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Palletsprojects Werkzeug | <2.2.3 | |
| debian/python-werkzeug | <=1.0.1+dfsg1-2<=2.2.2-2 | |
| debian/python-werkzeug | <=0.14.1+dfsg1-4+deb10u1 | 0.14.1+dfsg1-4+deb10u2 1.0.1+dfsg1-2+deb11u1 2.2.2-3 |
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Reference Links
- https://github.com/pallets/werkzeug/commit/cf275f42acad1b5950c50ffe8ef58fe62cdce028
- https://github.com/pallets/werkzeug/releases/tag/2.2.3
- https://github.com/pallets/werkzeug/security/advisories/GHSA-px8h-6qxv-m22q
- https://security.netapp.com/advisory/ntap-20230818-0003/
- https://www.debian.org/security/2023/dsa-5470
- https://nvd.nist.gov/vuln/detail/CVE-2023-23934
- https://github.com/advisories/GHSA-px8h-6qxv-m22q (Advisory)
- https://github.com/pallets/werkzeug/commit/8c2b4b82d0cade0d37e6a88e2cd2413878e8ebd4
- https://security-tracker.debian.org/tracker/CVE-2023-23934
- https://security-tracker.debian.org/tracker/CVE-2023-25577
- https://www.cve.org/CVERecord?id=CVE-2023-23934
- https://www.cve.org/CVERecord?id=CVE-2023-25577
- https://salsa.debian.org/python-team/packages/python-werkzeug/-/merge_requests/3
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1031370
Frequently Asked Questions
What is CVE-2023-23934?
CVE-2023-23934 is a vulnerability in Werkzeug that allows browsers to allow nameless cookies.
Which browsers are affected by CVE-2023-23934?
Any vulnerable browser that allows "nameless" cookies can be affected.
What is the severity of CVE-2023-23934?
The severity of CVE-2023-23934 is low, with a severity score of 3.5.
How can I fix CVE-2023-23934?
To fix CVE-2023-23934, update to Werkzeug version 2.2.3 or later.
Where can I find more information about CVE-2023-23934?
You can find more information about CVE-2023-23934 on the official GitHub page of Pallets Werkzeug.
- collector/nvd-api
- collector/github-advisory-latest
- alias/GHSA-px8h-6qxv-m22q
- alias/CVE-2023-23934
- collector/github-advisory
- collector/nvd-index
- collector/security-tracker-debian
- collector/debian-bugs
- collector/nvd-cve
- agent/type
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/weakness
- agent/last-modified-date
- agent/author
- agent/remedy
- agent/references
- agent/severity
- agent/title
- agent/tags
- agent/first-publish-date
- agent/event
- agent/description
- vendor/palletsprojects
- canonical/palletsprojects werkzeug
- package-manager/pip
- package-manager/debian