CVE-2023-3777: Use-after-free in Linux kernel's netfilter: nf_tables component

Published Sep 6, 2023
·
Updated

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

When nftablesdelrule() is flushing table rules, it is not checked whether the chain is bound and the chain's owner rule can also release the objects in certain circumstances.

We recommend upgrading past commit 6eaf41e87a223ae6f8e7a28d6e78384ad7e407f8.

Affected Software

14 affected componentsFixes available
redhat/Kernel<6.5
6.5
Linux Linux kernel>=5.9<5.10.188
Linux Linux kernel>=5.11<5.15.123
Linux Linux kernel>=5.16<6.1.42
Linux Linux kernel>=6.2<6.4.7
Debian Debian Linux=12.0
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=20.04
Canonical Ubuntu Linux=22.04
Linux Linux kernel<5.9.0
Linux Linux kernel>=6.0<6.5
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 6, 2023
CVE Published
via MITRE·01:50 PM
Data Sourced
via MITRE·01:50 PM
DescriptionSeverityWeakness
Data Sourced
via Red Hat·05:37 PM
DescriptionSeverityAffected Software
Jan 12, 2024
Data Sourced
via Launchpad·12:22 AM
Description
Apr 28, 2025
Data Sourced
via Ubuntu·02:14 PM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2023-3777?

CVE-2023-3777 is classified as a high-severity vulnerability due to its potential for local privilege escalation.

2

How do I fix CVE-2023-3777?

To mitigate CVE-2023-3777, update the kernel to a version higher than 6.5 or apply the latest patches provided by your distribution.

3

What systems are affected by CVE-2023-3777?

CVE-2023-3777 affects multiple versions of the Linux kernel, specifically versions between 5.9 and 6.5, including various distributions such as Debian and Ubuntu.

4

Can CVE-2023-3777 be exploited remotely?

CVE-2023-3777 is a local privilege escalation vulnerability and cannot be exploited remotely, requiring local access to the affected system.

5

What components of the Linux kernel does CVE-2023-3777 involve?

CVE-2023-3777 involves a use-after-free vulnerability in the Linux kernel's netfilter component, specifically in the nf_tables functionality.

Contact

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