CVE-2023-23934
Publication date 14 February 2023
Last updated 26 August 2025
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| python-werkzeug | ||
| 22.04 LTS jammy |
Fixed 2.0.2+dfsg1-1ubuntu0.22.04.1
|
|
| 20.04 LTS focal |
Fixed 0.16.1+dfsg1-2ubuntu0.1
|
|
| 18.04 LTS bionic |
Fixed 0.14.1+dfsg1-1ubuntu0.2
|
|
| 16.04 LTS xenial |
Fixed 0.10.4+dfsg1-1ubuntu1.2+esm1
|
|
| 14.04 LTS trusty | Ignored end of standard support |
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Get Ubuntu Pro 30-day free trialSeverity score breakdown
| Parameter | Value |
|---|---|
| Base score |
3.5 · Low
|
| Attack vector | Adjacent |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-5948-1
- Werkzeug vulnerabilities
- 13 March 2023
- USN-5948-2
- Werkzeug vulnerabilities
- 20 June 2023