CVE-2023-4004 Kernel: netfilter: use-after-free due to improper element removal in nft_pipapo_remove()

What is CVE-2023-4004?

CVE-2023-4004 is a high-severity use after free vulnerability in Debian Debian Linux, published on 31 Jul 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 in the way a user triggers the nft_pipapo_remove function with the element, without a NFT_SET_EXT_KEY_END. This issue could allow a local user to crash the system or potentially escalate their privileges on the system.

Weakness: CWE-416

Which versions are affected by CVE-2023-4004?

It affects 8 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp H300s, Netapp H410s, Netapp H500s and 2 more.

How do I fix CVE-2023-4004?

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-2023-4004 being exploited?

There is no known exploitation of CVE-2023-4004 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• 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-27796, DEBIAN-CVE-2023-4004, GHSA-h3j8-wx8r-29j6, UBUNTU-CVE-2023-4004.