CVE-2023-23454: Medium severity Linux Linux kernel vulnerability

Published Jan 1, 2023
·
Updated

An out-of-bounds (OOB) read problem was found in cbqclassify in net/sched/schcbq.c in the Linux kernel. This flaw allows a local attacker to cause a denial of service because of type confusion (non-negative numbers can sometimes indicate a TCACTSHOT condition rather than valid classification results).

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=caa4b35b4317d5147b3ab0fbdc9c075c7d2e9c12

Other sources

An out-of-bounds (OOB) read problem was found in cbqclassify in net/sched/schcbq.c in the Linux kernel. This issue may allow a local attacker to cause a denial of service due to type confusion. Non-negative numbers could indicate a TCACTSHOT condition rather than valid classification results.

cbqclassify in net/sched/schcbq.c in the Linux kernel through 6.1.4 allows attackers to cause a denial of service (slab-out-of-bounds read) because of type confusion (non-negative numbers can sometimes indicate a TCACTSHOT condition rather than valid classification results).

Affected Software

6 affected componentsFixes available
redhat/kernel-rt<0:4.18.0-477.10.1.rt7.274.el8_8
0:4.18.0-477.10.1.rt7.274.el8_8
redhat/kernel<0:4.18.0-477.10.1.el8_8
0:4.18.0-477.10.1.el8_8
Linux Linux kernel>=2.6.12<=6.1.4
Debian Debian Linux=11.0
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-16.12.27-1
redhat/kernel<6.2
6.2

Remediation

Information

The mitigation is to disable unprivileged user namespaces by setting user.max_user_namespaces to 0: ``` # echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf # sysctl -p /etc/sysctl.d/userns.conf ``` It is also possible to prevent the affected code from being loaded by blacklisting the `cbq` kernel module. For instructions on how to blacklist a kernel module, please see https://access.redhat.com/solutions/41278.

Event History

Jan 1, 2023
CVE Published
05:00 PM
Jan 12, 2023
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Feb 8, 2023
Data Sourced
via Red Hat·05:04 PM
DescriptionSeverityAffected Software
Jan 12, 2024
Data Sourced
via Launchpad·12:16 AM
Description
Apr 28, 2025
Data Sourced
via Ubuntu·02:10 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-2023-23454?

CVE-2023-23454 is rated as high severity due to its potential for causing denial of service.

2

How do I fix CVE-2023-23454?

To mitigate CVE-2023-23454, you should update to the patched versions of the affected Linux kernel versions mentioned in the advisory.

3

What versions are affected by CVE-2023-23454?

CVE-2023-23454 affects various versions of the Linux kernel, specifically versions prior to 4.18.0-477.10.1 and below 6.2.

4

Who can exploit CVE-2023-23454?

CVE-2023-23454 can be exploited by a local attacker with the ability to execute code on the affected system.

5

What systems are impacted by CVE-2023-23454?

CVE-2023-23454 impacts systems running affected versions of the Linux kernel, including distributions like Red Hat and Debian.

Contact

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