CVE-2023-4147 Kernel: netfilter: nf_tables_newrule when adding a rule with nfta_rule_chain_id leads to use-after-free

What is CVE-2023-4147?

CVE-2023-4147 is a high-severity use after free vulnerability in Debian Debian Linux, published on 7 Aug 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A use-after-free flaw was found in the Linux kernel’s Netfilter functionality when adding a rule with NFTA_RULE_CHAIN_ID. This flaw allows a local user to crash or escalate their privileges on the system.

Weakness: CWE-416

Which versions are affected by CVE-2023-4147?

It affects 8 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux for Real Time and 2 more.

How do I fix CVE-2023-4147?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2023-4147 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-4147 exists.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Debian Debian Linux

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• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-27897, CVE-2023-3995, DEBIAN-CVE-2023-4147, GHSA-pcv9-72q8-27vc, UBUNTU-CVE-2023-4147.