CVE-2021-3570
linuxptp: missing length check of forwarded messages
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · July 5, 2021
Updated · November 22, 2025
Description
A flaw was found in the ptp4l program of the linuxptp package. A missing length check when forwarding a PTP message between ports allows a remote attacker to cause an information leak, crash, or potentially remote code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Only attackers that can connect to the ptp4l service can exploit this vulnerability. If ptp4l is bound only to a private network interface, or is protected by firewall rules to block incoming PTP management messages, the attack surface is correspondingly limited. When using the UDP IPv4 or IPv6 network transport, the following tcpdump filter can be used to detect PTP management messages:
(port 319 or port 320) and udp[8]&0xf=0xd
CVSS / CWE
CVSS 3.1 · 8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer