CVE-2022-21682
Published: 13 January 2022
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`.
Priority
Status
Package | Release | Status |
---|---|---|
flatpak Launchpad, Ubuntu, Debian |
bionic |
Needs triage
|
focal |
Needs triage
|
|
hirsute |
Ignored
(end of life)
|
|
trusty |
Ignored
(end of standard support)
|
|
upstream |
Released
(1.12.3-1)
|
|
xenial |
Ignored
(end of standard support)
|
|
jammy |
Needs triage
|
|
impish |
Ignored
(end of life)
|
|
kinetic |
Ignored
(end of life, was needs-triage)
|
|
lunar |
Not vulnerable
(1.14.0-2)
|
|
mantic |
Not vulnerable
(1.14.0-2)
|
|
Patches: upstream: https://github.com/flatpak/flatpak/commit/445bddeee657fdc8d2a0a1f0de12975400d4fc1a upstream: https://github.com/flatpak/flatpak/commit/4d11f77aa7fd3e64cfa80af89d92567ab9e8e6fa |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.5 |
Attack vector | Network |
Attack complexity | Low |
Privileges required | Low |
User interaction | None |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | High |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |