QID 355398

Date Published: 2023-06-14

QID 355398: Amazon Linux Security Advisory for flatpak : ALAS2-2023-2076

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. (
( CVE-2021-41133)



Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

Successful exploitation of this vulnerability could lead to a securitybreach or could affect integrity, availability, and confidentiality.

  • CVSS V3 rated as High - 7.8 severity.
  • CVSS V2 rated as Medium - 4.6 severity.
    • Solution
    Please refer to Amazon advisory: ALAS2-2023-2076 for affected packages and patching details, or update with your package manager.
    Vendor References

    CVEs related to QID 355398

    CVE-2021-41133 |
    Software Advisories
    Advisory ID Software Component Link
    ALAS2-2023-2076 amazon linux 2 URL Logo alas.aws.amazon.com/AL2/ALAS-2023-2076.html
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