What is the CVSS score of CVE-2023-30861?

CVE-2023-30861 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. EPSS exploitation probability: 1.3%.

Is there a patch available for CVE-2023-30861?

Yes, a patch is available for CVE-2023-30861. Update the affected software to the latest version immediately.

Python CVE-2023-30861

HIGH

Use of Persistent Cookies Containing Sensitive Information (CWE-539)

2023-05-02 security-advisories@github.com

Python Information Disclosure Flask

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

CVE Published

May 02, 2023 - 18:15 nvd

HIGH 7.5

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

1 pypi packages depend on flask (1 direct, 0 indirect)

Ecosystem-wide dependent count for version 2.3.0.

DescriptionNVD

Flask is a lightweight WSGI web application framework. When all of the following conditions are met, a response containing data intended for one client may be cached and subsequently sent by the proxy to other clients. If the proxy also caches Set-Cookie headers, it may send one client's session cookie to other clients. The severity depends on the application's use of the session and the proxy's behavior regarding cookies. The risk depends on all these conditions being met.

The application must be hosted behind a caching proxy that does not strip cookies or ignore responses with cookies.
The application sets session.permanent = True
The application does not access or modify the session at any point during a request.
SESSION_REFRESH_EACH_REQUEST enabled (the default).
The application does not set a Cache-Control header to indicate that a page is private or should not be cached.

This happens because vulnerable versions of Flask only set the Vary: Cookie header when the session is accessed or modified, not when it is refreshed (re-sent to update the expiration) without being accessed or modified. This issue has been fixed in versions 2.3.2 and 2.2.5.

AnalysisAI

Flask is a lightweight WSGI web application framework. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.

Technical ContextAI

This vulnerability is classified under CWE-539. Flask is a lightweight WSGI web application framework. When all of the following conditions are met, a response containing data intended for one client may be cached and subsequently sent by the proxy to other clients. If the proxy also caches Set-Cookie headers, it may send one client's session cookie to other clients. The severity depends on the application's use of the session and the proxy's behavior regarding cookies. The risk depends on all these conditions being met. 1. The application must be hosted behind a caching proxy that does not strip cookies or ignore responses with cookies. 2. The application sets session.permanent = True 3. The application does not access or modify the session at any point during a request. 4. SESSION_REFRESH_EACH_REQUEST enabled (the default). 5. The application does not set a Cache-Control header to indicate that a page is private or should not be cached. This happens because vulnerable versions of Flask only set the Vary: Cookie header when the session is accessed or modified, not when it is refreshed (re-sent to update the expiration) without being accessed or modified. This issue has been fixed in versions 2.3.2 and 2.2.5. Affected products include: Palletsprojects Flask.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.