CentOS 7 : flatpak (RHSA-2021:0411)

high Nessus Plugin ID 146315

Synopsis

The remote CentOS Linux host is missing a security update.

Description

The remote CentOS Linux 7 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2021:0411 advisory.

- Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. A bug was discovered in the `flatpak-portal` service that can allow sandboxed applications to execute arbitrary code on the host system (a sandbox escape). This sandbox-escape bug is present in versions from 0.11.4 and before fixed versions 1.8.5 and 1.10.0. The Flatpak portal D-Bus service (`flatpak-portal`, also known by its D-Bus service name `org.freedesktop.portal.Flatpak`) allows apps in a Flatpak sandbox to launch their own subprocesses in a new sandbox instance, either with the same security settings as the caller or with more restrictive security settings. For example, this is used in Flatpak-packaged web browsers such as Chromium to launch subprocesses that will process untrusted web content, and give those subprocesses a more restrictive sandbox than the browser itself. In vulnerable versions, the Flatpak portal service passes caller-specified environment variables to non-sandboxed processes on the host system, and in particular to the `flatpak run` command that is used to launch the new sandbox instance. A malicious or compromised Flatpak app could set environment variables that are trusted by the `flatpak run` command, and use them to execute arbitrary code that is not in a sandbox. As a workaround, this vulnerability can be mitigated by preventing the `flatpak-portal` service from starting, but that mitigation will prevent many Flatpak apps from working correctly. This is fixed in versions 1.8.5 and 1.10.0. (CVE-2021-21261)

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://access.redhat.com/errata/RHSA-2021:0411

Plugin Details

Severity: High

ID: 146315

File Name: centos_RHSA-2021-0411.nasl

Version: 1.4

Type: local

Agent: unix

Published: 2/9/2021

Updated: 10/9/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.5

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2021-21261

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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

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

Vulnerability Information

CPE: p-cpe:/a:centos:centos:flatpak-libs, cpe:/o:centos:centos:7, p-cpe:/a:centos:centos:flatpak-builder, p-cpe:/a:centos:centos:flatpak, p-cpe:/a:centos:centos:flatpak-devel

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/CentOS/release, Host/CentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 2/9/2021

Vulnerability Publication Date: 1/14/2021

Reference Information

CVE: CVE-2021-21261

RHSA: 2021:0411