CVE-2021-43860

What it is

Flatpak is a Linux application sandboxing and distribution framework. Prior to versions 1.12.3 and 1.10.6, Flatpak doesn't properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, in the case that there's a null byte in the metadata file of an app. Therefore apps can grant themselves permissions without the consent of the user. Flatpak shows permissions to the user during install by reading them from the "xa.metadata" key in the commit metadata. This cannot contain a null terminator, because it is an untrusted GVariant. Flatpak compares these permissions to the *actual* metadata, from the "metadata" file to ensure it wasn't lied to. However, the actual metadata contents are loaded in several places where they are read as simple C-style strings. That means that, if the metadata file includes a null terminator, only the content of the file from *before* the terminator gets compared to xa.metadata. Thus, any permissions that appear in the metadata file after a null terminator are applied at runtime but not shown to the user. So maliciously crafted apps can give themselves hidden permissions. Users who have Flatpaks installed from untrusted sources are at risk in case the Flatpak has a maliciously crafted metadata file, either initially or in an update. This issue is patched in versions 1.12.3 and 1.10.6. As a workaround, users can manually check the permissions of installed apps by checking the metadata file or the xa.metadata key on the commit metadata.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

1.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2022-01-12 22:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:11 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.4% in the next 30 days (EPSS).
• Severity: 8.2 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2022-01-12 22:15 UTC

Last modified

2026-06-17 04:11 UTC

Exploit probability

1.4% · EPSS, next 30 days

Weakness

CWE-269 · Improper privilege management

Record status

Modified

Affected

• Flatpak < 1.10.6
• Flatpak ≤ 1.12.3
• Fedoraproject Fedora 35
• Redhat Enterprise Linux 8.0
• Debian Linux 9.0
• Debian Linux 10.0
• Debian Linux 11.0

Attack profile CVSS 3.1 · 8.2

Attack vector

Local

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-43860.md and follow it. Check whether this project is affected by CVE-2021-43860. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge