UBUNTU-CVE-2021-21381

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Source
https://ubuntu.com/security/CVE-2021-21381
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21381.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-21381
Related
Published
2021-03-11T17:15:00Z
Modified
2021-03-11T17:15:00Z
Severity
  • 8.2 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N CVSS Calculator
Summary
[none]
Details

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

Affected packages

Ubuntu:18.04:LTS / flatpak

Package

Name
flatpak
Purl
pkg:deb/ubuntu/flatpak?arch=src?distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.0.9-0ubuntu0.3

Affected versions

0.*

0.8.7-5
0.10.0-1
0.10.0-2
0.10.1-1
0.10.2-1
0.10.2.1-1
0.10.2.1-2
0.10.3-1
0.11.1-0ubuntu1
0.11.3-2
0.11.3-3
0.11.7-0ubuntu0.1

1.*

1.0.1-0ubuntu0.1
1.0.6-0ubuntu0.1
1.0.7-0ubuntu0.18.04.1
1.0.8-0ubuntu0.18.04.1
1.0.9-0ubuntu0.1
1.0.9-0ubuntu0.2

Ecosystem specific 

{
    "availability": "No subscription required",
    "ubuntu_priority": "medium",
    "binaries": [
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "flatpak"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "flatpak-dbgsym"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "flatpak-tests"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "flatpak-tests-dbgsym"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "gir1.2-flatpak-1.0"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "libflatpak-dev"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "libflatpak-doc"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "libflatpak0"
        },
        {
            "binary_version": "1.0.9-0ubuntu0.3",
            "binary_name": "libflatpak0-dbgsym"
        }
    ]
}

Ubuntu:20.04:LTS / flatpak

Package

Name
flatpak
Purl
pkg:deb/ubuntu/flatpak?arch=src?distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.6.5-0ubuntu0.3

Affected versions

1.*

1.4.3-1
1.6.0-1
1.6.1-1
1.6.2-1
1.6.3-1
1.6.5-0ubuntu0.1
1.6.5-0ubuntu0.2

Ecosystem specific 

{
    "availability": "No subscription required",
    "ubuntu_priority": "medium",
    "binaries": [
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "flatpak"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "flatpak-dbgsym"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "flatpak-tests"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "flatpak-tests-dbgsym"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "gir1.2-flatpak-1.0"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "libflatpak-dev"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "libflatpak-doc"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "libflatpak0"
        },
        {
            "binary_version": "1.6.5-0ubuntu0.3",
            "binary_name": "libflatpak0-dbgsym"
        }
    ]
}