Debian DLA-3536-1 : flask - LTS security update

high Nessus Plugin ID 180017

Synopsis

The remote Debian host is missing a security-related update.

Description

The remote Debian 10 host has packages installed that are affected by a vulnerability as referenced in the dla-3536 advisory.

- 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. (CVE-2023-30861)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade the flask packages.

For Debian 10 buster, this problem has been fixed in version 1.0.2-3+deb10u1.

See Also

https://security-tracker.debian.org/tracker/source-package/flask

https://www.debian.org/lts/security/2023/dla-3536

https://security-tracker.debian.org/tracker/CVE-2023-30861

https://packages.debian.org/source/buster/flask

Plugin Details

Severity: High

ID: 180017

File Name: debian_DLA-3536.nasl

Version: 1.1

Type: local

Agent: unix

Published: 8/22/2023

Updated: 10/16/2023

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

CVSS Score Source: CVE-2023-30861

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:python3-flask, p-cpe:/a:debian:debian_linux:python-flask, p-cpe:/a:debian:debian_linux:python-flask-doc, cpe:/o:debian:debian_linux:10.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/20/2023

Vulnerability Publication Date: 5/2/2023

Reference Information

CVE: CVE-2023-30861