Sandbox bypass via recent VFS-manipulating syscalls

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.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

输入验证不恰当

Flatpak 安全漏洞

Flatpak是一套用于Linux桌面应用计算机环境的应用程序虚拟化系统。 Flatpak 1.12.0和1.10.4之前版本存在安全漏洞，该漏洞源于可直接访问AF_UNIX套接字（如Wayland、Pipewire或Pipewire pulse使用的套接字）的Flatpak应用程序可以欺骗门户和其他主机操作系统服务，使其将Flatpak应用程序视为普通的、非沙盒主机操作系统进程。1.10.4版和1.12.0版都有补丁，正在计划1.8.2版的补丁。除了升级到修补版本外，没有其他解决办法。

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