CVE-2023-39192: Linux Kernel Netfilter Xtables Out-Of-Bounds Read Information Disclosure Vulnerability

Published Jul 26, 2023
·
Updated

A flaw was found in the Netfilter subsystem in the Linux kernel. The xtu32 module did not validate the fields in the xtu32 structure. This flaw allows a local privileged attacker to trigger an out-of-bounds read by setting the size fields with a value beyond the array boundaries, leading to a crash or information disclosure.

Other sources

An out-of-bounds read issue was found in the Linux kernel in the u32matchit() function, which is used to match packet content under netfilter. 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 u32matchit function in Netfilter Xtables. By sending a specially crafted request, an attacker could exploit this vulnerability to obtain sensitive information, and use this information to launch further attacks against the affected system.

IBM

This vulnerability allows local attackers to disclose sensitive information on affected installations of the Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the u32matchit function. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the kernel.

ZDI

Affected Software

10 affected componentsFixes available
Linux Kernel
Linux Linux kernel<6.6
redhat Enterprise Linux=8.0
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
redhat/kernel<6.6
6.6

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·02:13 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
Feb 26, 2025
Advisory Published
via ZDI·03:45 PM
May 2, 2025
Data Sourced
via Ubuntu·02:14 PM
RemedyDescriptionSeverityAffected Software
Mar 9, 2026
Advisory Published
via ZDI·10:23 PM
Data Sourced
via ZDI·10:23 PM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the vulnerability ID for this vulnerability?

The vulnerability ID for this vulnerability is CVE-2023-39192.

2

What is the title of this vulnerability?

The title of this vulnerability is Linux Kernel Netfilter Xtables Out-Of-Bounds Read Information Disclosure Vulnerability.

3

What is the severity of CVE-2023-39192?

The severity of CVE-2023-39192 is medium.

4

How can an attacker exploit this vulnerability?

An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability.

5

What is the affected software?

The affected software includes Linux Kernel versions up to 6.6, Redhat Enterprise Linux version 8.0, and Fedoraproject Fedora version 38.

Contact

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