CVE-2020-14367

MEDIUM

chrony < 3.5.1 - Denial of Service via PID File Symlink Attack

Title source: llm
STIX 2.1

Description

A flaw was found in chrony versions before 3.5.1 when creating the PID file under the /var/run/chrony folder. The file is created during chronyd startup while still running as the root user, and when it's opened for writing, chronyd does not check for an existing symbolic link with the same file name. This flaw allows an attacker with privileged access to create a symlink with the default PID file name pointing to any destination file in the system, resulting in data loss and a denial of service due to the path traversal.

References (4)

Core 4
Core References
Issue Tracking, Patch, Vendor Advisory x_refsource_misc
https://bugzilla.redhat.com/show_bug.cgi?id=1870298
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202008-23
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/4475-1/

Scores

CVSS v3 6.0
EPSS 0.0027
EPSS Percentile 50.9%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H

Details

CWE
CWE-59
Status published
Products (4)
canonical/ubuntu_linux 18.04
canonical/ubuntu_linux 20.04
fedoraproject/fedora 32
tuxfamily/chrony < 3.5.1
Published Aug 24, 2020
Tracked Since Feb 18, 2026