Description
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation.

When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue().

We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
Published: 2023-09-12
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-3623-1 linux-5.10 security update
Debian DLA Debian DLA DLA-3710-1 linux security update
EUVD EUVD EUVD-2023-54757 A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
Ubuntu USN Ubuntu USN USN-6439-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6439-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-3 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-2 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6442-1 Linux kernel (BlueField) vulnerabilities
Ubuntu USN Ubuntu USN USN-6444-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6444-2 Linux kernel (StarFive) vulnerabilities
Ubuntu USN Ubuntu USN USN-6445-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6445-2 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-3 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6454-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6454-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6454-3 Linux kernel (ARM laptop) vulnerabilities
Ubuntu USN Ubuntu USN USN-6454-4 Linux kernel (StarFive) vulnerabilities
Ubuntu USN Ubuntu USN USN-6461-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6466-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6479-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6699-1 Linux kernel vulnerabilities
History

Fri, 27 Feb 2026 02:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 13 Feb 2025 17:30:00 +0000

Type Values Removed Values Added
Description A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8. A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.

Subscriptions

Debian Debian Linux
Linux Linux Kernel
Redhat Enterprise Linux Rhel Aus Rhel E4s Rhel Els Rhel Eus Rhel Extras Rt Rhel Tus Rhev Hypervisor
cve-icon MITRE

Status: PUBLISHED

Assigner: Google

Published:

Updated: 2026-02-25T17:20:09.498Z

Reserved: 2023-09-12T19:22:10.389Z

Link: CVE-2023-4921

cve-icon Vulnrichment

Updated: 2024-08-02T07:44:52.210Z

cve-icon NVD

Status : Modified

Published: 2023-09-12T20:15:10.573

Modified: 2025-02-13T18:15:48.687

Link: CVE-2023-4921

cve-icon Redhat

Severity : Important

Publid Date: 2023-09-05T00:00:00Z

Links: CVE-2023-4921 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses