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TencentOS Server 4: python-flask (TSSA-2025:0162)

medium Nessus Plugin ID 239485

Synopsis

The remote TencentOS Server 4 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2025:0162 advisory.

 Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

 CVE-2023-30861:
 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.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

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

Solution

Update the affected packages.

See Also

https://mirrors.tencent.com/tlinux/errata/tssa-20250162.xml

Plugin Details

Severity: Medium

ID: 239485

File Name: tencentos_TSSA_2025_0162.nasl

Version: 1.3

Type: local

Published: 6/16/2025

Updated: 12/4/2025

Supported Sensors: 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

CVSS v4

Risk Factor: Medium

Base Score: 6.3

Threat Score: 2.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: p-cpe:/a:tencent:tencentos_server:python-flask, cpe:/o:tencent:tencentos_server:4

Required KB Items: Host/local_checks_enabled, Host/etc/os-release, Host/TencentOS/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/25/2025

Vulnerability Publication Date: 2/25/2025

Reference Information

CVE: CVE-2023-30861