Linux Kernel up to 6.6.x Netfilter nf_tables_api.c nft_trans_gc_catchall use after free

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.x. It has been classified as critical. This affects the function nft_trans_gc_catchall of the file net/netfilter/nf_tables_api.c of the component Netfilter. The manipulation leads to use after free. This vulnerability is traded as CVE-2023-6111. An attack has to be approached locally. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.x (Operating System). It has been rated as critical. This issue affects the function nft_trans_gc_catchall of the file net/netfilter/nf_tables_api.c of the component Netfilter. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. The function nft_trans_gc_catchall did not remove the catchall set element from the catchall_list when the argument sync is true, making it possible to free a catchall set element many times. We recommend upgrading past commit 93995bf4af2c5a99e2a87f0cd5ce547d31eb7630.

The weakness was shared 11/14/2023 by Lonial Kong. It is possible to read the advisory at kernel.dance. The identification of this vulnerability is CVE-2023-6111 since 11/13/2023. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/17/2025).

The vulnerability scanner Nessus provides a plugin with the ID 250207 (Linux Distros Unpatched Vulnerability : CVE-2023-6111), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.7 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (250207). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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