Flatpak vulnerable to a sandbox escape via RequestBackground portal due to bad argument parsing

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. in versions before 1.10.9, 1.12.9, 1.14.6, and 1.15.8, a malicious or compromised Flatpak app could execute arbitrary code outside its sandbox. Normally, the `--command` argument of `flatpak run` expects to be given a command to run in the specified Flatpak app, optionally along with some arguments. However it is possible to instead pass `bwrap` arguments to `--command=`, such as `--bind`. It's possible to pass an arbitrary `commandline` to the portal interface `org.freedesktop.portal.Background.RequestBackground` from within a Flatpak app. When this is converted into a `--command` and arguments, it achieves the same effect of passing arguments directly to `bwrap`, and thus can be used for a sandbox escape. The solution is to pass the `--` argument to `bwrap`, which makes it stop processing options. This has been supported since bubblewrap 0.3.0. All supported versions of Flatpak require at least that version of bubblewrap. xdg-desktop-portal version 1.18.4 will mitigate this vulnerability by only allowing Flatpak apps to create .desktop files for commands that do not start with --. The vulnerability is patched in 1.15.8, 1.10.9, 1.12.9, and 1.14.6.

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

参数注入或修改

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 1.10.9、1.12.9、1.14.6 和 1.15.8 之前版本存在安全漏洞，该漏洞源于将 Flatpak 与 xdg-desktop-portal 结合使用时可能导致沙箱逃逸。

N/A

N/A