CVE-2021-21381
Description
A sandbox escape flaw was found in the way flatpak handled special tokens in ".desktop" files. This flaw allows an attacker to gain access to files that are not ordinarily allowed by the app's permissions. The highest threat from this vulnerability is to confidentiality and integrity.
Statement
This is essentially a sandbox escape flaw and needs a malicious app publisher to execute the exploit.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | 8.2 | N/A |
| Attack Vector | Network | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | Required | N/A |
| Scope | Unchanged | Changed | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
Frequently Asked Questions
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