---
title: "CVE-2021-22600: Double Free in net/packet/af_packet.c… | CubePath"
description: "A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny…"
language: en
source: https://cubepath.com/security/cve/CVE-2021-22600
---

# CVE-2021-22600: Double Free in net/packet/af_packet.c… | CubePath

## Description

A double free bug in packet\_set\_ring() in net/packet/af\_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

Official description from the CVE record, published by Google. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-22600)

## Key data

### CVSS 3.1 Medium 6.6

Score published by Google in the CVE record.

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H

| Metric                 | Value    | What it means                                                                             |
| ---------------------- | -------- | ----------------------------------------------------------------------------------------- |
| Attack vector          | Local    | The attacker needs local access to the system, or to trick a user into running something. |
| Attack complexity      | High     | The attack depends on conditions outside the attacker's control, so it takes preparation. |
| Privileges required    | Low      | A basic user account is needed.                                                           |
| User interaction       | Required | A user has to do something first, such as opening a file or following a link.             |
| Scope                  | Changed  | The impact can reach other components beyond the vulnerable one.                          |
| Confidentiality impact | Low      | Limited effect on the secrecy of data.                                                    |
| Integrity impact       | Low      | Limited effect on the trustworthiness of data.                                            |
| Availability impact    | High     | Serious or total effect on availability.                                                  |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.06586 (6.6% probability)

Percentile

93.9%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

Linux Kernel Privilege Escalation Vulnerability

Added to the catalog

Apr 11, 2022

Federal due date

May 2, 2022

### CISA assessment as of Jan 29, 2025

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

no

Technical impact

partial

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-415](https://cwe.mitre.org/data/definitions/415.html) Double Free

## Affected products

Products listed in the CVE record, as the CNA published them.

- Linux Kernel Kernel

  - affected: unspecified up to before 5.4.168
  - affected: unspecified up to before 5.10.88
  - affected: unspecified up to before 5.15.11
  - affected: unspecified up to before 5.16-rc6

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/…](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=ec6af094ea28f0f2dda1a6a33b14cd57e36a9755)
- [\[debian-lts-announce\] 20220309 \[SECURITY\] \[DLA 2941-1\] linux-4.19 security update](https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html)  (lists.debian.org) mailing-list
- [DSA-5096](https://www.debian.org/security/2022/dsa-5096)  (debian.org) vendor-advisory
- [security.netapp.com/advisory/ntap-20230110-0002](https://security.netapp.com/advisory/ntap-20230110-0002/)

## Timeline

1. ID reserved Jan 5, 2021
2. Record published Jan 26, 2022
3. Added to CISA KEV Apr 11, 2022
4. Record last updated Oct 21, 2025

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:30 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)