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[USN-7612-1] Flask-CORS vulnerabilities

Posted on 03 July 2025
Ubuntu Security

==========================================================================Ubuntu Security Notice USN-7612-1
July 02, 2025

python-flask-cors vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.04
- Ubuntu 24.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in Flask-CORS.

Software Description:
- python-flask-cors: Flask extension for handling Cross Origin Resource Sharing (CORS)

Details:

It was discovered that Flask-CORS did not correctly handle certain regular
expressions. A remote attacker could possibly use this issue to leak
sensitive information or bypass authentication mechanisms. (CVE-2024-6839)
It was discovered that Flask-CORS allowed certain CORS headers to be
enabled by default. A remote attacker could possibly use this issue to leak
sensitive information. This issue only affected Ubuntu 20.04 LTS, Ubuntu
22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 24.10. (CVE-2024-6221) It was
discovered that Flask-CORS did not correctly handle case sensitivity when
matching paths. A remote attacker could possibly use this issue to leak
sensitive information. (CVE-2024-6866) It was discovered that Flask-CORS
did not correctly handle certain characters in URL paths. A remote attacker
could possibly use this issue to leak sensitive information or bypass
authentication mechanisms. (CVE-2024-6844) Elias Hohl was discovered that
Flask-CORS did not correctly sanitize log entries. A remote attacker could
possibly use this issue to corrupt log files. This issue only affected
Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2024-1681)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 25.04
python3-flask-cors 5.0.0-1ubuntu0.1

Ubuntu 24.10
python3-flask-cors 4.0.1-1ubuntu0.1

Ubuntu 24.04 LTS
python3-flask-cors 4.0.0-1ubuntu0.1~esm1
Available with Ubuntu Pro

Ubuntu 22.04 LTS
python3-flask-cors 3.0.9-2ubuntu0.1

Ubuntu 20.04 LTS
python3-flask-cors 3.0.8-2ubuntu0.1+esm1
Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-7612-1
CVE-2024-1681, CVE-2024-6221, CVE-2024-6839, CVE-2024-6844,
CVE-2024-6866

Package Information:
https://launchpad.net/ubuntu/+source/python-flask-cors/5.0.0-1ubuntu0.1
https://launchpad.net/ubuntu/+source/python-flask-cors/4.0.1-1ubuntu0.1
https://launchpad.net/ubuntu/+source/python-flask-cors/3.0.9-2ubuntu0.1

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