CVE-2021-21381

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
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
Configurations

Configuration 1 (hide)

cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

Configuration 3 (hide)

OR cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

History

21 Nov 2024, 05:48

Type Values Removed Values Added
CVSS v2 : 5.8
v3 : 8.2
v2 : 5.8
v3 : 7.1
References () https://github.com/flatpak/flatpak/commit/8279c5818425b6812523e3805bbe242fb6a5d961 - Patch, Third Party Advisory () https://github.com/flatpak/flatpak/commit/8279c5818425b6812523e3805bbe242fb6a5d961 - Patch, Third Party Advisory
References () https://github.com/flatpak/flatpak/commit/a7401e638bf0c03102039e216ab1081922f140ae - Patch, Third Party Advisory () https://github.com/flatpak/flatpak/commit/a7401e638bf0c03102039e216ab1081922f140ae - Patch, Third Party Advisory
References () https://github.com/flatpak/flatpak/commit/eb7946bb6248923d8c90fe9b84425fef97ae580d - Patch, Third Party Advisory () https://github.com/flatpak/flatpak/commit/eb7946bb6248923d8c90fe9b84425fef97ae580d - Patch, Third Party Advisory
References () https://github.com/flatpak/flatpak/pull/4156 - Patch, Third Party Advisory () https://github.com/flatpak/flatpak/pull/4156 - Patch, Third Party Advisory
References () https://github.com/flatpak/flatpak/releases/tag/1.10.2 - Release Notes, Third Party Advisory () https://github.com/flatpak/flatpak/releases/tag/1.10.2 - Release Notes, Third Party Advisory
References () https://github.com/flatpak/flatpak/security/advisories/GHSA-xgh4-387p-hqpp - Third Party Advisory () https://github.com/flatpak/flatpak/security/advisories/GHSA-xgh4-387p-hqpp - Third Party Advisory
References () 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/2MXXLXC2DPJ45HSMTI5MZYHMYEGQN6AA/ -
References () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXNVFOIB6ZP4DGOVKAM25T6OIEP3YLGV/ - () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXNVFOIB6ZP4DGOVKAM25T6OIEP3YLGV/ -
References () https://security.gentoo.org/glsa/202312-12 - () https://security.gentoo.org/glsa/202312-12 -
References () https://www.debian.org/security/2021/dsa-4868 - Third Party Advisory () https://www.debian.org/security/2021/dsa-4868 - Third Party Advisory

23 Dec 2023, 10:15

Type Values Removed Values Added
References
  • () https://security.gentoo.org/glsa/202312-12 -

07 Nov 2023, 03:29

Type Values Removed Values Added
References
  • {'url': 'https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2MXXLXC2DPJ45HSMTI5MZYHMYEGQN6AA/', 'name': 'FEDORA-2021-fe7decc595', 'tags': ['Mailing List', 'Third Party Advisory'], 'refsource': 'FEDORA'}
  • {'url': 'https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WXNVFOIB6ZP4DGOVKAM25T6OIEP3YLGV/', 'name': 'FEDORA-2021-26ad138ffa', 'tags': ['Mailing List', 'Third Party Advisory'], 'refsource': 'FEDORA'}
  • () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WXNVFOIB6ZP4DGOVKAM25T6OIEP3YLGV/ -
  • () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2MXXLXC2DPJ45HSMTI5MZYHMYEGQN6AA/ -

Information

Published : 2021-03-11 17:15

Updated : 2024-11-21 05:48


NVD link : CVE-2021-21381

Mitre link : CVE-2021-21381

CVE.ORG link : CVE-2021-21381


JSON object : View

Products Affected

debian

  • debian_linux

flatpak

  • flatpak

fedoraproject

  • fedora
CWE
CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')