CVE Vulnerabilities

CVE-2021-3899

Time-of-check Time-of-use (TOCTOU) Race Condition

Published: Jun 03, 2024 | Modified: Aug 26, 2025
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

There is a race condition in the replaced executable detection that, with the correct local configuration, allow an attacker to execute arbitrary code as root.

Weakness

The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check.

Affected Software

Name Vendor Start Version End Version
Apport Canonical * 2.21.0 (excluding)
Apport Ubuntu bionic *
Apport Ubuntu devel *
Apport Ubuntu esm-infra-legacy/trusty *
Apport Ubuntu esm-infra/bionic *
Apport Ubuntu esm-infra/focal *
Apport Ubuntu esm-infra/xenial *
Apport Ubuntu focal *
Apport Ubuntu hirsute *
Apport Ubuntu impish *
Apport Ubuntu jammy *
Apport Ubuntu kinetic *
Apport Ubuntu lunar *
Apport Ubuntu mantic *
Apport Ubuntu noble *
Apport Ubuntu oracular *
Apport Ubuntu plucky *
Apport Ubuntu questing *
Apport Ubuntu trusty/esm *
Apport Ubuntu upstream *

Potential Mitigations

References