What’s Vulnerable › Vulnerabilities

CVE-2021-3571

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-09 · updated 2026-06-17
• Weakness: CWE-119

Description

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: 33, 34
• Linuxptp Project Linuxptp: before 2.0.1; from 3.0 before 3.1.1 — fixed in 2.0.1, 3.1.1
• Red Hat Enterprise Linux: 8.0

How to fix

Upgrade to a fixed version: Linuxptp Project Linuxptp 2.0.1, 3.1.1. Check the vendor advisory for mitigations.

References

• https://bugzilla.redhat.com/show_bug.cgi?id=1966241
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RHRUVSDP673LXJ5HGIPQPWPIYUPWYQA7/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUBKTRCMJ6VKS7DIBSZQB4ATSKVCJYXJ/
• https://bugzilla.redhat.com/show_bug.cgi?id=1966241
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RHRUVSDP673LXJ5HGIPQPWPIYUPWYQA7/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUBKTRCMJ6VKS7DIBSZQB4ATSKVCJYXJ/

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