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HIGH

Use-after-free in Linux kernel's net/sched: cls_fw component

Published Jul 21, 2023

Description

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

If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.

Affected products

Remediation

Red Hat mitigation

To mitigate this issue, prevent module cls_fw from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.

Weaknesses (1)

CWE-416

Use After Free

References (14)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner Google
Published Jul 21, 2023
Updated Mar 5, 2025
Reserved Jul 19, 2023
Link CVE-2023-3776
CISA Vulnrichment
Updated Mar 5, 2025
NVD
Status Modified
Modified Jun 17, 2026
Link CVE-2023-3776
Red Hat
Severity Important
Public date Jul 6, 2023
Links CVE-2023-3776 - Bugzilla
ENISA EUVD
Assigner Google
Published Jul 21, 2023
Updated Mar 5, 2025
Exploited since n/a
Link EUVD-2023-44409
EUVD-2023-44409