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.
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Flatpak | Flatpak | 0.11.4 (including) | 1.8.5 (excluding) |
| Flatpak | Flatpak | 1.9.1 (including) | 1.10.0 (excluding) |
| Red Hat Enterprise Linux 7 | RedHat | flatpak-0:1.0.9-10.el7_9 | * |
| Red Hat Enterprise Linux 8 | RedHat | flatpak-0:1.6.2-5.el8_3 | * |
| Red Hat Enterprise Linux 8.1 Extended Update Support | RedHat | flatpak-0:1.0.9-3.el8_1 | * |
| Red Hat Enterprise Linux 8.2 Extended Update Support | RedHat | flatpak-0:1.6.2-4.el8_2 | * |
| Flatpak | Ubuntu | bionic | * |
| Flatpak | Ubuntu | devel | * |
| Flatpak | Ubuntu | focal | * |
| Flatpak | Ubuntu | groovy | * |
| Flatpak | Ubuntu | trusty | * |