8.6

CVE-2021-43860: debian debian_linux Improper Privilege Management

CVSS: 8.6v3.1HighModified
AliasesRHSA-2022:1792UBUNTU-CVE-2021-43860DEBIAN-CVE-2021-43860
Published 12-01-2022Last modified 04-08-2024
Open JSON

Vulnerability summary

CVE-2021-43860 is a high (CVSS 8.6) Improper Privilege Management vulnerability in debian debian_linux. EPSS estimates a 1.34% chance of exploitation in the next 30 days, higher than 70.9% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (NVD)
EPSS score
1.34%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 3
DSA-5049-1MGASA-2022-0131OPENSUSE-SU-2022:0712-1SUSE-SU-2022:0712-1SUSE-SU-2022:3284-1

Timeline

  1. 12-01-2022
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

1.34%

Chance of exploitation in the next 30 days

Percentile

71%

Versus all other CVEs

30-day change

-0.01 pp

From 1.35% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Redhat11 products
  • enterprise_linux8.0
  • flatpak< 0:1.8.7-1.el8
  • flatpak-debuginfo< 0:1.8.7-1.el8
  • flatpak-debugsource< 0:1.8.7-1.el8
  • flatpak-devel< 0:1.8.7-1.el8
Debian2 products
Fedoraproject1 product
Flatpak1 product
  • flatpak≥ 1.11.0, < 1.12.3 | < 1.10.6 | ≥ 1.11.1, ≤ 1.12.3
Opensuse1 product
  • flatpak&distro=openSUSE Tumbleweed< 1.12.3-1.1
Ubuntu1 product
  • flatpakAll versions (No fix recorded)

6 vendors · 17 products

References

24 links
Show all 24 references