CVE-2022-21682 – flatpak-builder can access files outside the build directory.

https://notcve.org/view.php?id=CVE-2022-21682

Flatpak is a Linux application sandboxing and distribution framework. A path traversal vulnerability affects versions of Flatpak prior to 1.12.3 and 1.10.6. flatpak-builder applies `finish-args` last in the build. At this point the build directory will have the full access that is specified in the manifest, so running `flatpak build` against it will gain those permissions. Normally this will not be done, so this is not problem. However, if `--mirror-screenshots-url` is specified, then flatpak-builder will launch `flatpak build --nofilesystem=host appstream-utils mirror-screenshots` after finalization, which can lead to issues even with the `--nofilesystem=host` protection. • https://github.com/flatpak/flatpak/commit/445bddeee657fdc8d2a0a1f0de12975400d4fc1a https://github.com/flatpak/flatpak/commit/4d11f77aa7fd3e64cfa80af89d92567ab9e8e6fa https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APFTBYGJJVJPFVHRXUW5PII5XOAFI4KH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IXKBERLJRYV7KXKGXOLI6IOXVBQNN4DP https://security.gentoo.org/glsa/202312-12 https://www.debian • CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') •