Related Vulnerabilities: CVE-2021-21381  

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.

Severity Medium

Remote No

Type Sandbox escape

Description

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.

AVG-1678 flatpak 1.10.1-1 1.10.2-1 Medium Fixed

https://github.com/flatpak/flatpak/security/advisories/GHSA-xgh4-387p-hqpp
https://github.com/flatpak/flatpak/issues/4146
https://github.com/flatpak/flatpak/pull/4156
https://github.com/flatpak/flatpak/commit/8279c5818425b6812523e3805bbe242fb6a5d961