CVE-2023-4015: Use-after-free in Linux kernel's netfilter: nf_tables component

Published Sep 6, 2023
·
Updated

A use-after-free vulnerability in the Linux kernel's netfilter: nftables component can be exploited to achieve local privilege escalation.

On an error when building a nftables rule, deactivating immediate expressions in nftimmediatedeactivate() can lead unbinding the chain and objects be deactivated but later used.

We recommend upgrading past commit 0a771f7b266b02d262900c75f1e175c7fe76fec2.

Affected Software

8 affected componentsFixes available
redhat/Kernel<6.5
6.5
Linux Linux kernel>=5.9<5.10.190
Linux Linux kernel>=5.11<5.15.124
Linux Linux kernel>=5.16<6.1.43
Linux Linux kernel>=6.2<6.4.8
Debian Debian Linux=12.0
Linux Linux kernel<=6.5
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-16.12.27-1

Remediation

Mitigation

If not needed, disable the ability for unprivileged users to create namespaces. To do this temporarily, do: sudo sysctl -w kernel.unprivileged_userns_clone=0 To disable across reboots, do: echo kernel.unprivileged_userns_clone=0 | \ sudo tee /etc/sysctl.d/99-disable-unpriv-userns.conf

Event History

Sep 6, 2023
CVE Published
via MITRE·01:52 PM
Data Sourced
via MITRE·01:52 PM
DescriptionSeverityWeakness
Data Sourced
via Red Hat·05:37 PM
DescriptionSeverityAffected Software
Jan 12, 2024
Data Sourced
via Launchpad·12:24 AM
Description
Apr 28, 2025
Data Sourced
via Ubuntu·02:14 PM
RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2023-4015?

The severity of CVE-2023-4015 is relatively high due to its potential for local privilege escalation.

2

How do I fix CVE-2023-4015?

To fix CVE-2023-4015, update the Linux kernel to version 6.5 or apply the necessary patches as specified by your distribution.

3

Which systems are affected by CVE-2023-4015?

CVE-2023-4015 affects various versions of the Linux kernel, specifically from 5.9 to 6.5, and certain Debian Linux versions.

4

What type of vulnerability is CVE-2023-4015?

CVE-2023-4015 is classified as a use-after-free vulnerability in the netfilter nf_tables component.

5

Can CVE-2023-4015 be exploited remotely?

CVE-2023-4015 is primarily a local privilege escalation vulnerability and cannot be exploited remotely.

Contact

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