CVE-2023-42754: Kernel: ipv4: null pointer dereference in ipv4_send_dest_unreach()

Published Sep 20, 2023
·
Updated

A flaw was found in ipv4senddestunreach() due to NULL pointer derefence due to a missing edge-case check.

Other sources

A NULL pointer dereference flaw was found in the Linux kernel ipv4 stack. The socket buffer (skb) was assumed to be associated with a device before calling ipoptionscompile, which is not always the case if the skb is re-routed by ipvs. This issue may allow a local user with CAPNETADMIN privileges to crash the system.

Launchpad

Linux Kernel is vulnerable to a denial of service, caused by a NULL pointer dereference flaw in the ipv4senddestunreach function in net/ipv4/route.c. By sending a specially crafted request, a local authenticated attacker could exploit this vulnerability to cause a denial of service condition.

IBM

Affected Software

14 affected componentsFixes available
redhat/kernel<6.6
6.6
Linux Linux kernel<6.6
Linux Linux kernel=6.6-rc1
Linux Linux kernel=6.6-rc2
redhat Enterprise Linux=8.0
redhat Enterprise Linux=9.0
Fedoraproject Fedora=37
Fedoraproject Fedora=38
Fedoraproject Fedora=39
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
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-1

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 20, 2023
Data Sourced
via Red Hat·01:52 PM
DescriptionSeverityAffected Software
Oct 5, 2023
CVE Published
via MITRE·06:25 PM
Data Sourced
via MITRE·06:25 PM
DescriptionSeverityWeakness
May 31, 2024
Data Sourced
via Launchpad·02:33 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 the severity of CVE-2023-42754?

CVE-2023-42754 has been categorized as a medium severity vulnerability.

2

How do I fix CVE-2023-42754?

To fix CVE-2023-42754, update the Linux kernel or the specific affected packages to versions that include the patch.

3

Which systems are affected by CVE-2023-42754?

CVE-2023-42754 affects various versions of the Linux kernel up to 6.6 and specific releases of Red Hat Enterprise Linux, Fedora, and Debian.

4

What causes the vulnerability in CVE-2023-42754?

CVE-2023-42754 is caused by a NULL pointer dereference in the ipv4_send_dest_unreach() function due to a missing edge-case check.

5

Is there a workaround for CVE-2023-42754?

There is no documented workaround for CVE-2023-42754; upgrading to a fixed version is the recommended approach.

Contact

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