CVE catalog
CVE-2021-21381
flatpak: CVE-2021-21381
- Severity
- High · CVSS 8.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 1.55% · Oct 25, 2026
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`.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | flatpak | sid | 1.18.4-1 | fixed |
| Debian | flatpak | forky | 1.18.4-1 | fixed |
| Debian | flatpak | trixie | 1.16.6-1~deb13u2 | fixed |
| Debian | flatpak | trixie-security | 1.16.6-1~deb13u3 | fixed |
| Debian | flatpak | bookworm | 1.14.10-1~deb12u2 | fixed |
| Debian | flatpak | bookworm-security | 1.14.10-1~deb12u2 | fixed |
| Ubuntu | flatpak | 18.04 | 0.8.7-5 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.0-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.0-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.1-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2.1-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2.1-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.3-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.1-0ubuntu1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.3-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.3-3 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.7-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.1-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.6-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.7-0ubuntu0.18.04.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.8-0ubuntu0.18.04.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.3 | fixed |
| Ubuntu | flatpak | 20.04 | 1.4.3-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.0-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.1-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.2-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.3-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.2 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.3 | fixed |
| Ubuntu | flatpak | 18.04 | 0.8.7-5 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.0-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.0-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.1-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2.1-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.2.1-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.10.3-1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.1-0ubuntu1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.3-2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.3-3 | vulnerable |
| Ubuntu | flatpak | 18.04 | 0.11.7-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.1-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.6-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.7-0ubuntu0.18.04.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.8-0ubuntu0.18.04.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.2 | vulnerable |
| Ubuntu | flatpak | 18.04 | 1.0.9-0ubuntu0.3 | fixed |
| Ubuntu | flatpak | 20.04 | 1.4.3-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.0-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.1-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.2-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.3-1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.1 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.2 | vulnerable |
| Ubuntu | flatpak | 20.04 | 1.6.5-0ubuntu0.3 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | flatpak | source | sid | 1.10.1-4 | not yet assigned | Not reported | [984859] |
| Debian | flatpak | source | forky | 1.10.1-4 | not yet assigned | Not reported | [984859] |
| Debian | flatpak | source | trixie | 1.10.1-4 | not yet assigned | Not reported | [984859] |
| Debian | flatpak | source | bookworm | 1.10.1-4 | not yet assigned | Not reported | [984859] |
| Ubuntu | flatpak | deb | 18.04 | 1.0.9-0ubuntu0.3 | Not reported | UBUNTU-CVE-2021-21381 | Not reported |
| Ubuntu | flatpak | deb | 20.04 | 1.6.5-0ubuntu0.3 | Not reported | UBUNTU-CVE-2021-21381 | Not reported |
| Ubuntu | flatpak | deb | 18.04 | 1.0.9-0ubuntu0.3 | Not reported | USN-4951-1 | Not reported |
| Ubuntu | flatpak | deb | 20.04 | 1.6.5-0ubuntu0.3 | Not reported | USN-4951-1 | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
[Debian 12 (Bookworm)]
- [flatpak]Unknown
Details (6)
1.14.10-1~deb12u2· amd64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· amd64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· arm64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· amd64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
- [flatpak-tests]Unknown
Source package: [flatpak]
Details (6)
1.14.10-1~deb12u2· amd64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· amd64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· arm64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· amd64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
- [gir1.2-flatpak-1.0]Unknown
Source package: [flatpak]
Details (6)
1.14.10-1~deb12u2· amd64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· amd64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· arm64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· amd64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
- [libflatpak0]Unknown
Source package: [flatpak]
Details (6)
1.14.10-1~deb12u2· amd64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· amd64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· arm64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· amd64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
- [libflatpak-dev]Unknown
Source package: [flatpak]
Details (6)
1.14.10-1~deb12u2· amd64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· amd64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· arm64 · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· amd64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· arm64 · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
- [libflatpak-doc]Unknown
Source package: [flatpak]
Details (6)
1.14.10-1~deb12u2· all · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· all · bookwormFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· all · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.16.6-1~deb13u1~bpo12+1· all · bookworm-backportsFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· all · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
1.14.10-1~deb12u2· all · bookworm-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · bookworm; dsa · flatpak · debian · 12
[Debian 13 (Trixie)]
- [flatpak]Unknown
Details (6)
1.16.6-1~deb13u1· amd64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· arm64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· arm64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· amd64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
- [flatpak-tests]Unknown
Source package: [flatpak]
Details (6)
1.16.6-1~deb13u1· amd64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· arm64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· arm64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· amd64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
- [gir1.2-flatpak-1.0]Unknown
Source package: [flatpak]
Details (6)
1.16.6-1~deb13u1· amd64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· arm64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· arm64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· amd64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
- [libflatpak0]Unknown
Source package: [flatpak]
Details (6)
1.16.6-1~deb13u1· amd64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· arm64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· arm64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· amd64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
- [libflatpak-dev]Unknown
Source package: [flatpak]
Details (6)
1.16.6-1~deb13u1· amd64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· arm64 · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· amd64 · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· arm64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· amd64 · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
- [libflatpak-doc]Unknown
Source package: [flatpak]
Details (6)
1.16.6-1~deb13u1· all · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· all · trixieFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u1· all · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· all · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u2· all · trixie-security · Historical versionFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
1.16.6-1~deb13u3· all · trixie-securityFixed · Fixed:
1.10.1-4dsa · flatpak · debian · 13
Observed:
References
- [https://access.redhat.com/errata/RHSA-2021:1073]
- [https://ftp.suse.com/pub/projects/security/csaf/rhsa-2021_1002.json]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-21381]
- [https://osv.dev/vulnerability/DSA-4868-1]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-21381]
- [https://osv.dev/vulnerability/USN-4951-1]
- [https://security-tracker.debian.org/tracker/CVE-2021-21381]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]