CVE-2023-4206

kernel: net/sched: Use-after-free vulnerabilities in the net/sched classifiers: cls_fw, cls_u32 and cls_route

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Severity

Important

Red Hat Product Security

7.8

CVSS 3.1

Review impact separately from score.

Published · July 29, 2023

Updated · August 7, 2026

Description

There are 3 CVEs for the use-after-free flaw found in net/sched/cls_fw.c in classifiers (cls_fw, cls_u32, and cls_route) in the Linux Kernel: CVE-2023-4206, CVE-2023-4207, CVE-2023-4208. A local user could use any of these flaws to crash the system or potentially escalate their privileges on the system.

Similar CVE-2023-4128 was rejected as a duplicate.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

To mitigate this issue, prevent the module cls_u32 from being loaded by blacklisting the module to prevent it from loading automatically.

https://access.redhat.com/solutions/41278

CVSS / CWE

CVSS 3.1 · 7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE-416 · Use After Free