CVE-2021-3571: Fedoraproject Fedora

High severity, CVSS 7.1. EPSS: 1.9% chance of exploitation in the next 30 days.

A flaw was found in the ptp4l program of the linuxptp package. When ptp4l is operating on a little-endian architecture as a PTP transparent clock, a remote attacker could send a crafted one-step sync message to cause an information leak or crash. The highest threat from this vulnerability is to data confidentiality and system availability. This flaw affects linuxptp versions before 3.1.1 and before 2.0.1.

Affected products

• Fedoraproject Fedora: version 33 only; version 34 only
• Linuxptp Project Linuxptp: before 2.0.1 (fixed in 2.0.1); from 3.0, before 3.1.1 (fixed in 3.1.1)
• Red Hat Enterprise Linux: version 8.0 only

Published 2021-07-09. Last modified 2026-06-17.