Debian DSA-4984-1 : flatpak - security update

high Nessus Plugin ID 154148

Synopsis

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

Description

The remote Debian 11 host has packages installed that are affected by a vulnerability as referenced in the dsa-4984 advisory.

- Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In versions prior to 1.10.4 and 1.12.0, Flatpak apps with direct access to AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can trick portals and other host-OS services into treating the Flatpak app as though it was an ordinary, non-sandboxed host-OS process. They can do this by manipulating the VFS using recent mount-related syscalls that are not blocked by Flatpak's denylist seccomp filter, in order to substitute a crafted `/.flatpak-info` or make that file disappear entirely. Flatpak apps that act as clients for AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can escalate the privileges that the corresponding services will believe the Flatpak app has. Note that protocols that operate entirely over the D-Bus session bus (user bus), system bus or accessibility bus are not affected by this. This is due to the use of a proxy process `xdg-dbus-proxy`, whose VFS cannot be manipulated by the Flatpak app, when interacting with these buses. Patches exist for versions 1.10.4 and 1.12.0, and as of time of publication, a patch for version 1.8.2 is being planned. There are no workarounds aside from upgrading to a patched version. (CVE-2021-41133)

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 flatpak packages.

For the stable distribution (bullseye), this problem has been fixed in version 1.10.5-0+deb11u1.

See Also

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=995935

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

https://www.debian.org/security/2021/dsa-4984

https://security-tracker.debian.org/tracker/CVE-2021-41133

https://packages.debian.org/source/bullseye/flatpak

Plugin Details

Severity: High

ID: 154148

File Name: debian_DSA-4984.nasl

Version: 1.3

Type: local

Agent: unix

Published: 10/14/2021

Updated: 1/20/2022

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2021-41133

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:flatpak, p-cpe:/a:debian:debian_linux:flatpak-tests, p-cpe:/a:debian:debian_linux:gir1.2-flatpak-1.0, p-cpe:/a:debian:debian_linux:libflatpak-dev, p-cpe:/a:debian:debian_linux:libflatpak-doc, p-cpe:/a:debian:debian_linux:libflatpak0, cpe:/o:debian:debian_linux:11.0

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/12/2021

Vulnerability Publication Date: 10/8/2021

Reference Information

CVE: CVE-2021-41133