---
title: "CVE-2021-3571\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2021-3571?format=md
keywords: index, follow
---

# CVE-2021-3571

Publication date 5 July 2021

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.1 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2021-3571?format=md#impact-score)

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## 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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| linuxptp | 23.04 lunar | Not affected |
| 22.10 kinetic | Not affected |
| 22.04 LTS jammy | Not affected |
| 21.10 impish | Not affected |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Not affected |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2021-3571?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| linuxptp | * Upstream:   [d61d77e](https://github.com/richardcochran/linuxptp/commit/d61d77e163dbee247819f3d88593ba111577af15) * Upstream:   [0b3ab45](https://github.com/richardcochran/linuxptp/commit/0b3ab45de6a96ca181a5cf62c3c2b97167e2ed20) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.1 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | Low |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | Low |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.1 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3571)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2021-3571)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2021-3571)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2021-3571)

### Other references

* <https://www.openwall.com/lists/oss-security/2021/07/06/1>
* <https://www.cve.org/CVERecord?id=CVE-2021-3571>