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Huawei EulerOS: CVE-2021-41133: flatpak security update

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Huawei EulerOS: CVE-2021-41133: flatpak security update

Severity
5
CVSS
(AV:L/AC:L/Au:N/C:P/I:P/A:P)
Published
10/08/2021
Created
12/29/2021
Added
12/28/2021
Modified
12/28/2021

Description

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.

Solution(s)

  • huawei-euleros-2_0_sp8-upgrade-flatpak
  • huawei-euleros-2_0_sp8-upgrade-flatpak-libs

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