CVE-2022-21682 flatpak-builder can access files outside the build directory.
A malicious application can exploit path traversal in flatpak-builder to execute arbitrary code or modify files outside the build directory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-21682?
CVE-2022-21682 is a high-severity path traversal vulnerability in Debian Debian Linux, published on 13 Jan 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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. In normal use, the only issue is that these empty directories can be created wherever the user has write permissions. However, a malicious application could replace the `appstream-util` binary and potentially do something more hostile. This has been resolved in Flatpak 1.12.3 and 1.10.6 by changing the behaviour of `--nofilesystem=home` and `--nofilesystem=host`.
Weakness: CWE-22
Which versions are affected by CVE-2022-21682?
It affects 5 products.
Linux distribution packages (7)
flatpak-builder AlmaLinux:8 | All versions | 1.0.14-2.el8 |
flatpak-builder Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.14-2.el8 |
flatpak-builder-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.14-2.el8 |
flatpak-builder-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.14-2.el8 |
flatpak-builder Rocky Linux:8 | All versions | 0:1.0.14-2.el8 |
flatpak openSUSE:Tumbleweed | All versions | 1.12.4-1.1 |
flatpak-builder openSUSE:Tumbleweed | All versions | 1.2.2-1.1 |
Products include Debian Debian Linux, Fedoraproject Fedora, Flatpak Flatpak, Flatpak Flatpak-Builder, Redhat Enterprise Linux.
How do I fix CVE-2022-21682?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2022-21682 being exploited?
There is no known exploitation of CVE-2022-21682 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALSA-2022:7458, CLEANSTART-2024-GX04243, DEBIAN-CVE-2022-21682, GHSA-8ch7-5j3h-g4fx, OESA-2022-1788, RHSA-2022:7458 and 4 more.