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FreeBSD: VID-719F06AF-E45E-11EA-95A1-C3B8167B8026 (CVE-2020-14367): chrony <= 3.5.1 data corruption through symlink vulnerability writing the pidfile

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FreeBSD: VID-719F06AF-E45E-11EA-95A1-C3B8167B8026 (CVE-2020-14367): chrony &lt;= 3.5.1 data corruption through symlink vulnerability writing the pidfile

Severity
4
CVSS
(AV:L/AC:L/Au:N/C:N/I:P/A:P)
Published
08/06/2020
Created
08/25/2020
Added
08/23/2020
Modified
10/20/2020

Description

Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.

From VID-719F06AF-E45E-11EA-95A1-C3B8167B8026:

Miroslav Lichvar reports:

chrony-3.5.1 [...] fixes a security issue in writing of the pidfile.

When chronyd is configured to save the pidfile in a directory where the

chrony user has write permissions (e.g. /var/run/chrony - the default

since chrony-3.4), an attacker that compromised the chrony user account

could create a symbolic link at the location of the pidfile to make

chronyd starting with root privileges follow the symlink and write its

process ID to a file for which the chrony user doesn't have write

permissions, causing a denial of service, or data loss.

This issue was reported by Matthias Gerstner of SUSE.

Solution(s)

  • freebsd-upgrade-package-chrony

References

  • CVE-2020-14367

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