CVE-2023-4921

Updated: 2025-08-20 02:32:45.887032

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.


Links NIST CIRCL RHEL Ubuntu

Severity

Severity Score
CVSS Version 2.x 0.0
CVSS Version 3.x HIGH 7.8

Status

OS name Project name Version Score Severity Status Errata Last updated

Statement

AlmaLinux 9.2 ESU kernel 5.14.0 7.8 HIGH Not Vulnerable 2024-01-20 10:09:27
CentOS 6 ELS kernel 2.6.32 7.8 HIGH Released CLSA-2024:1724774331 2024-09-09 12:27:01
CentOS 7 ELS kernel 3.10.0 7.8 HIGH Already Fixed 2024-07-01 11:35:41
CentOS 8.4 ELS kernel 4.18.0 7.8 HIGH Released CLSA-2023:1701963303 2023-12-07 13:13:52
CentOS 8.5 ELS kernel 4.18.0 7.8 HIGH Released CLSA-2023:1701962635 2023-12-07 13:13:53
CloudLinux 6 ELS kernel 2.6.32 7.8 HIGH Ignored 2024-10-09 04:04:26
Oracle Linux 6 ELS kernel 2.6.32 7.8 HIGH Released CLSA-2024:1725187614 2024-09-01 12:25:03
Ubuntu 16.04 ELS linux-hwe 4.15.0 7.8 HIGH Released CLSA-2023:1695902773 2023-09-28 09:30:11
Ubuntu 16.04 ELS linux 4.4.0 7.8 HIGH Released CLSA-2023:1695901231 2023-09-28 09:30:09
Ubuntu 18.04 ELS linux 4.15.0 7.8 HIGH Released CLSA-2023:1695900880 2023-09-28 09:30:10