CVE-2022-21682

flatpak-builder can access files outside the build directory.

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`.

Category

7.7
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.27%
Vendor Advisory fedoraproject.org Vendor Advisory debian.org Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org
Affected: flatpak flatpak
Published at:
Updated at:

References

Link Tags
https://github.com/flatpak/flatpak/security/advisories/GHSA-8ch7-5j3h-g4fx third party advisory patch
https://github.com/flatpak/flatpak/commit/445bddeee657fdc8d2a0a1f0de12975400d4fc1a third party advisory patch
https://github.com/flatpak/flatpak/commit/4d11f77aa7fd3e64cfa80af89d92567ab9e8e6fa third party advisory patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APFTBYGJJVJPFVHRXUW5PII5XOAFI4KH/ vendor advisory
https://www.debian.org/security/2022/dsa-5049 third party advisory vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IXKBERLJRYV7KXKGXOLI6IOXVBQNN4DP/ vendor advisory
https://security.gentoo.org/glsa/202312-12 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2022-21682?
CVE-2022-21682 has been scored as a high severity vulnerability.
How to fix CVE-2022-21682?
To fix CVE-2022-21682, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2022-21682 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2022-21682 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2022-21682?
CVE-2022-21682 affects flatpak flatpak.
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