CVE-2023-6817: Fixes in Linux Kernel

Published Dec 18, 2023
·
Updated

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

The function nftpipapowalk did not skip inactive elements during set walk which could lead double deactivations of PIPAPO (Pile Packet Policies) elements, leading to use-after-free.

We recommend upgrading past commit 317eb9685095678f2c9f5a8189de698c5354316a.

Other sources

Linux Kernel could allow a local authenticated attacker to gain elevated privileges on the system, caused by a use-after-free flaw in the nftpipapowalk function in the netfilter: nftables component. By sending a specially crafted request, an authenticated attacker could exploit this vulnerability to gain elevated privileges.

IBM

Affected Software

11 affected componentsFixes available
Linux Linux kernel>=5.6<5.10.204
Linux Linux kernel>=5.11<5.15.143
Linux Linux kernel>=5.16<6.1.68
Linux Linux kernel>=6.2<6.6.7
Linux Linux kernel=6.7-rc1
Linux Linux kernel=6.7-rc2
Linux Linux kernel=6.7-rc3
Linux Linux kernel=6.7-rc4
IBM Security Verify Governance, Identity Manager software component<=ISVG 10.0.2
IBM Security Verify Governance, Identity Manager virtual appliance component<=ISVG 10.0.2
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

Dec 18, 2023
CVE Published
via MITRE·02:37 PM
Data Sourced
via MITRE·02:37 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·08:20 PM
DescriptionSeverityAffected Software
Feb 7, 2024
Data Sourced
12:00 AM
SeverityWeakness
Feb 14, 2024
Data Sourced
via Launchpad·10:43 PM
Description
Apr 30, 2025
Data Sourced
via Ubuntu·11:51 PM
RemedyDescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2023-6817?

CVE-2023-6817 has a high severity level due to its potential for local privilege escalation.

2

How do I fix CVE-2023-6817?

To fix CVE-2023-6817, update to the recommended Linux kernel versions or later as specified in the vulnerability details.

3

Which systems are affected by CVE-2023-6817?

CVE-2023-6817 affects multiple versions of the Linux kernel and specific IBM Security Verify Governance products.

4

What exploitation method is associated with CVE-2023-6817?

CVE-2023-6817 can be exploited via a use-after-free condition in the nf_tables component of the Linux kernel.

5

What are the consequences of CVE-2023-6817 if exploited?

Exploitation of CVE-2023-6817 can lead to local privilege escalation, allowing unauthorized users to gain elevated access to the system.

Contact

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