Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In Flatpack since version 0.9.4 and before version 1.10.2 has a vulnerability in the "file forwarding" feature which can be used by an attacker to gain access to files that would not ordinarily be allowed by the app's permissions. By putting the special tokens `@@` and/or `@@u` in the Exec field of a Flatpak app's .desktop file, a malicious app publisher can trick flatpak into behaving as though the user had chosen to open a target file with their Flatpak app, which automatically makes that file available to the Flatpak app. This is fixed in version 1.10.2. A minimal solution is the first commit "`Disallow @@ and @@U usage in desktop files`". The follow-up commits "`dir: Reserve the whole @@ prefix`" and "`dir: Refuse to export .desktop files with suspicious uses of @@ tokens`" are recommended, but not strictly required. As a workaround, avoid installing Flatpak apps from untrusted sources, or check the contents of the exported `.desktop` files in `exports/share/applications/*.desktop` (typically `~/.local/share/flatpak/exports/share/applications/*.desktop` and `/var/lib/flatpak/exports/share/applications/*.desktop`) to make sure that literal filenames do not follow `@@` or `@@u`.
References
Link | Resource |
---|---|
https://github.com/flatpak/flatpak/commit/8279c5818425b6812523e3805bbe242fb6a5d961 | Patch Third Party Advisory |
https://github.com/flatpak/flatpak/commit/a7401e638bf0c03102039e216ab1081922f140ae | Patch Third Party Advisory |
https://github.com/flatpak/flatpak/commit/eb7946bb6248923d8c90fe9b84425fef97ae580d | Patch Third Party Advisory |
https://github.com/flatpak/flatpak/pull/4156 | Patch Third Party Advisory |
https://github.com/flatpak/flatpak/releases/tag/1.10.2 | Release Notes Third Party Advisory |
https://github.com/flatpak/flatpak/security/advisories/GHSA-xgh4-387p-hqpp | Third Party Advisory |
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2MXXLXC2DPJ45HSMTI5MZYHMYEGQN6AA/ | |
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXNVFOIB6ZP4DGOVKAM25T6OIEP3YLGV/ | |
https://security.gentoo.org/glsa/202312-12 | |
https://www.debian.org/security/2021/dsa-4868 | Third Party Advisory |
History
No history.
MITRE Information
Status: PUBLISHED
Assigner: GitHub_M
Published: 2021-03-11T00:00:00
Updated: 2023-12-23T10:06:19.370583
Reserved: 2020-12-22T00:00:00
Link: CVE-2021-21381
JSON object: View
NVD Information
Status : Modified
Published: 2021-03-11T17:15:12.703
Modified: 2023-12-23T10:15:08.370
Link: CVE-2021-21381
JSON object: View
Redhat Information
No data.
CWE