CVE-2021-21261HIGH
Description
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.
References
https://github.com/flatpak/flatpak/commit/6d1773d2a54dde9b099043f07a2094a4f1c2f486
https://github.com/flatpak/flatpak/commit/6e5ae7a109cdfa9735ea7ccbd8cb79f9e8d3ae8b
https://github.com/flatpak/flatpak/commit/aeb6a7ab0abaac4a8f4ad98b3df476d9de6b8bd4
https://github.com/flatpak/flatpak/commit/cc1401043c075268ecc652eac557ef8076b5eaba
https://github.com/flatpak/flatpak/releases/tag/1.8.5
https://github.com/flatpak/flatpak/security/advisories/GHSA-4ppf-fxf6-vxg2
Details
Source: MITRE
Published: 2021-01-14
Updated: 2021-01-27
Type: CWE-74
Risk Information
CVSS v2.0
Base Score: 7.2
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C
Impact Score: 10
Exploitability Score: 3.9
Severity: HIGH
CVSS v3.0
Base Score: 8.8
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Impact Score: 6
Exploitability Score: 2
Severity: HIGH
Tenable Plugins
| ID | Name | Product | Family | Severity |
|---|---|---|---|---|
| 148417 | openSUSE Security Update : flatpak / libostree / xdg-desktop-portal / etc (openSUSE-2021-520) | Nessus | SuSE Local Security Checks | high |
| 148387 | SUSE SLED15 / SLES15 Security Update : flatpak, libostree, xdg-desktop-portal, xdg-desktop-portal-gtk (SUSE-SU-2021:1094-1) | Nessus | SuSE Local Security Checks | high |
| 146624 | Amazon Linux 2 : flatpak (ALAS-2021-1597) | Nessus | Amazon Linux Local Security Checks | high |
| 146315 | CentOS 7 : flatpak (CESA-2021:0411) | Nessus | CentOS Local Security Checks | high |
| 146270 | Scientific Linux Security Update : flatpak on SL7.x x86_64 (2021:0411) | Nessus | Scientific Linux Local Security Checks | high |
| 146210 | RHEL 7 : flatpak (RHSA-2021:0411) | Nessus | Red Hat Local Security Checks | high |
| 146208 | Ubuntu 18.04 LTS / 20.04 LTS / 20.10 : Flatpak vulnerability (USN-4721-1) | Nessus | Ubuntu Local Security Checks | high |
| 146195 | Oracle Linux 7 : flatpak (ELSA-2021-0411) | Nessus | Oracle Linux Local Security Checks | high |
| 146089 | CentOS 8 : flatpak (CESA-2021:0304) | Nessus | CentOS Local Security Checks | high |
| 146046 | Oracle Linux 8 : flatpak (ELSA-2021-0304) | Nessus | Oracle Linux Local Security Checks | high |
| 145790 | RHEL 8 : flatpak (RHSA-2021:0307) | Nessus | Red Hat Local Security Checks | high |
| 145787 | RHEL 8 : flatpak (RHSA-2021:0306) | Nessus | Red Hat Local Security Checks | high |
| 145704 | RHEL 8 : flatpak (RHSA-2021:0304) | Nessus | Red Hat Local Security Checks | high |
| 145369 | GLSA-202101-21 : Flatpak: Sandbox escape | Nessus | Gentoo Local Security Checks | high |
| 145021 | Debian DSA-4830-1 : flatpak - security update | Nessus | Debian Local Security Checks | high |