Upstream information

CVE-2021-21261 at MITRE


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.

SUSE information

Overall state of this security issue: Analysis

This issue is currently rated as having important severity.

CVSS v2 Scores
  National Vulnerability Database
Base Score 7.2
Vector AV:L/AC:L/Au:N/C:C/I:C/A:C
Access Vector Local
Access Complexity Low
Authentication None
Confidentiality Impact Complete
Integrity Impact Complete
Availability Impact Complete
CVSS v3 Scores
  National Vulnerability Database SUSE
Base Score 8.8 7.3
Access Vector Local Local
Access Complexity Low Low
Privileges Required Low Low
User Interaction None None
Scope Changed Changed
Confidentiality Impact High High
Integrity Impact High Low
Availability Impact High None
CVSSv3 Version 3.1 3.1
SUSE Bugzilla entry: 1180996 [NEW]

SUSE Security Advisories:

List of released packages

Product(s) Fixed package version(s) References
SUSE Linux Enterprise Module for Basesystem 15 SP2
  • libostree-1-1 >= 2020.8-3.3.2
SUSE Linux Enterprise Module for Desktop Applications 15 SP2
  • flatpak >= 1.10.2-4.6.1
  • flatpak-devel >= 1.10.2-4.6.1
  • flatpak-zsh-completion >= 1.10.2-4.6.1
  • libflatpak0 >= 1.10.2-4.6.1
  • libostree >= 2020.8-3.3.2
  • libostree-devel >= 2020.8-3.3.2
  • system-user-flatpak >= 1.10.2-4.6.1
  • typelib-1_0-Flatpak-1_0 >= 1.10.2-4.6.1
  • typelib-1_0-OSTree-1_0 >= 2020.8-3.3.2
  • xdg-desktop-portal >= 1.8.0-5.3.2
  • xdg-desktop-portal-devel >= 1.8.0-5.3.2
  • xdg-desktop-portal-gtk >= 1.8.0-3.3.1
  • xdg-desktop-portal-gtk-lang >= 1.8.0-3.3.1
  • xdg-desktop-portal-lang >= 1.8.0-5.3.2
SUSE Linux Enterprise Module for Open Buildservice Development Tools 15 SP2
  • libostree-grub2 >= 2020.8-3.3.2
openSUSE Leap 15.2
  • flatpak >= 1.10.2-lp152.3.6.1
  • flatpak-debuginfo >= 1.10.2-lp152.3.6.1
  • flatpak-debugsource >= 1.10.2-lp152.3.6.1
  • flatpak-devel >= 1.10.2-lp152.3.6.1
  • flatpak-zsh-completion >= 1.10.2-lp152.3.6.1
  • libflatpak0 >= 1.10.2-lp152.3.6.1
  • libflatpak0-debuginfo >= 1.10.2-lp152.3.6.1
  • libostree >= 2020.8-lp152.2.3.1
  • libostree-1-1 >= 2020.8-lp152.2.3.1
  • libostree-1-1-debuginfo >= 2020.8-lp152.2.3.1
  • libostree-debuginfo >= 2020.8-lp152.2.3.1
  • libostree-debugsource >= 2020.8-lp152.2.3.1
  • libostree-devel >= 2020.8-lp152.2.3.1
  • libostree-grub2 >= 2020.8-lp152.2.3.1
  • system-user-flatpak >= 1.10.2-lp152.3.6.1
  • typelib-1_0-Flatpak-1_0 >= 1.10.2-lp152.3.6.1
  • typelib-1_0-OSTree-1_0 >= 2020.8-lp152.2.3.1
  • xdg-desktop-portal >= 1.8.0-lp152.4.3.1
  • xdg-desktop-portal-debuginfo >= 1.8.0-lp152.4.3.1
  • xdg-desktop-portal-debugsource >= 1.8.0-lp152.4.3.1
  • xdg-desktop-portal-devel >= 1.8.0-lp152.4.3.1
  • xdg-desktop-portal-gtk >= 1.8.0-lp152.2.3.1
  • xdg-desktop-portal-gtk-debuginfo >= 1.8.0-lp152.2.3.1
  • xdg-desktop-portal-gtk-debugsource >= 1.8.0-lp152.2.3.1
  • xdg-desktop-portal-gtk-lang >= 1.8.0-lp152.2.3.1
  • xdg-desktop-portal-lang >= 1.8.0-lp152.4.3.1

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification.

Product(s) Source package State
SUSE CaaS Platform 4.0 flatpak Affected
SUSE Enterprise Storage 6 flatpak Affected
SUSE Linux Enterprise High Performance Computing 15 LTSS flatpak Analysis
SUSE Linux Enterprise High Performance Computing 15 SP1 LTSS flatpak Affected
SUSE Linux Enterprise Module for Desktop Applications 15 SP1 flatpak Unsupported
SUSE Linux Enterprise Module for Desktop Applications 15 SP2 flatpak Released
SUSE Linux Enterprise Server 15 LTSS flatpak Analysis
SUSE Linux Enterprise Server 15 SP1 Business Critical Linux flatpak Affected
SUSE Linux Enterprise Server 15 SP1 LTSS flatpak Affected
SUSE Linux Enterprise Server ESPOS 15 flatpak Analysis
SUSE Linux Enterprise Server for SAP Applications 15 flatpak Analysis
SUSE Linux Enterprise Server for SAP Applications 15 SP1 flatpak Affected
SUSE Manager Proxy 4.0 flatpak Affected
SUSE Manager Retail Branch Server 4.0 flatpak Affected
SUSE Manager Server 4.0 flatpak Affected