CVE-2023-39189: Kernel: netfilter: nftables out-of-bounds read in nf_osf_match_one()

Published Jul 26, 2023
·
Updated

A flaw was found in the Netfilter subsystem in the Linux kernel. The nfnlosfaddcallback function did not validate the user mode controlled optnum field. This flaw allows a local privileged (CAPNETADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.

Other sources

An out-of-bounds read issue was found in the Linux kernel in the nfosfmatchone() function, which is used for nftables OS fingerprinting. This flaw requires CAPNETADMIN to be exploited and could lead to information disclosure.

Red Hat

Linux Kernel could allow a local authenticated attacker to obtain sensitive information, caused by an out-of-bounds read flaw in the nfnlosfaddcallback function in the Netfilter subsystem. By sending a specially crafted request, an attacker could exploit this vulnerability to obtain sensitive information or cause a denial of service condition.

IBM

Affected Software

10 affected componentsFixes available
redhat/kernel<6.6
6.6
Linux Linux kernel<6.6
redhat Enterprise Linux=8.0
redhat Enterprise Linux=9.0
Fedoraproject Fedora=38
IBM Security Verify Governance<=ISVG 10.0.2
IBM Security Verify Governance, Identity Manager Software Stack<=ISVG 10.0.2
IBM Security Verify Governance, Identity Manager Virtual Appliance<=ISVG 10.0.2
IBM Security Verify Governance Identity Manager Container<=ISVG 10.0.2
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.27-1

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

Jul 26, 2023
Data Sourced
via Red Hat·01:40 PM
DescriptionSeverityAffected Software
Oct 9, 2023
CVE Published
via MITRE·05:57 PM
Data Sourced
via MITRE·05:57 PM
DescriptionSeverityWeakness
May 31, 2024
Data Sourced
via Launchpad·02:32 AM
Description
Apr 28, 2025
Data Sourced
via Ubuntu·02:14 PM
RemedyDescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2023-39189?

CVE-2023-39189 is a vulnerability found in the Netfilter subsystem in the Linux kernel that allows a local privileged attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.

2

How severe is CVE-2023-39189?

CVE-2023-39189 has a severity rating of medium with a value of 6.

3

Which software is affected by CVE-2023-39189?

The Linux kernel versions up to 6.6, Redhat Enterprise Linux versions 8.0 and 9.0, and Fedora version 38 are affected by CVE-2023-39189.

4

How can I fix CVE-2023-39189?

To fix CVE-2023-39189, it is recommended to update the affected software to a version that includes the patch for this vulnerability.

5

Where can I find more information about CVE-2023-39189?

You can find more information about CVE-2023-39189 on the Redhat Security Advisory page and the Bugzilla entry.

Contact

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