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CVE-2021-22600

Double Free in net/packet/af_packet.c leading to priviledge escalation

CVSS 3.1 Medium 6.6Known exploited (CISA KEV)

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

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 for the CVE license. View the record on cve.org

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

  • 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.

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 for the CWE license.

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.

Timeline

  1. ID reserved
  2. Record published
  3. Added to CISA KEV
  4. Record last updated

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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, 19:29 UTC. Sources and licenses