CVE-2021-21381 Vulnerability Details

  /     /     /  

CVE-2021-21381 Metadata Quick Info

CVE Published: 11/03/2021 | CVE Updated: 03/08/2024 | CVE Year: 2021
Source: GitHub_M | Vendor: flatpak | Product: flatpak
Status : PUBLISHED

CVE-2021-21381 Description

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`.

Metrics

CVSS Version: 3.1 | Base Score: 7.1 HIGH
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N

l➤ Exploitability Metrics:
    Attack Vector (AV)* LOCAL
    Attack Complexity (AC)* LOW
    Privileges Required (PR)* NONE
    User Interaction (UI)* REQUIRED
    Scope (S)* CHANGED

l➤ Impact Metrics:
    Confidentiality Impact (C)* LOW
    Integrity Impact (I)* HIGH
    Availability Impact (A)* NONE

Weakness Enumeration (CWE)

CWE-ID: CWE-74
CWE Name: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ( Injection )
Source: flatpak

Common Attack Pattern Enumeration and Classification (CAPEC)

CAPEC-ID:
CAPEC Description:


Source: NVD (National Vulnerability Database).