cbcvebase.
CVE-2021-41133
published 2021-10-08

CVE-2021-41133: 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…

PriorityP343high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.41%
32.4th percentile
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.

Affected

17 ranges
VendorProductVersion rangeFixed in
debiandebian_linux
debiandebian_linux
debianflatpak< flatpak 1.12.1-1 (bookworm)flatpak 1.12.1-1 (bookworm)
debianwebkit2gtk< webkit2gtk 2.34.1-1 (bookworm)webkit2gtk 2.34.1-1 (bookworm)
debianwpewebkit< webkit2gtk 2.34.1-1 (bookworm)webkit2gtk 2.34.1-1 (bookworm)
fedoraprojectfedora
fedoraprojectfedora
fedoraprojectfedora
flatpakflatpak< 1.8.21.8.2
flatpakflatpak>= 0 < 1.10.5-0+deb11u11.10.5-0+deb11u1
flatpakflatpak>= 0 < 1.12.1-11.12.1-1
flatpakflatpak>= 0 < 1.12.1-11.12.1-1
flatpakflatpak>= 0 < 1.12.1-11.12.1-1
flatpakflatpak>= 1.10.0 < 1.10.41.10.4
flatpakflatpak>= 1.11.1 < 1.12.11.12.1
webkitgtkwebkitgtk< 2.34.12.34.1
wpewebkitwpe_webkit< 2.34.12.34.1

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.04.6MEDIUMAV:L/AC:L/Au:N/C:P/I:P/A:P
osv7.8HIGH
vendor_debian8.8HIGH
vendor_redhat8.8HIGH
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