CVE-2023-4569: Kernel: information leak in nft_set_catchall_flush in net/netfilter/nf_tables_api.c

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-08-28 · updated 2026-06-17
Weakness: CWE-402

Description

A memory leak flaw was found in nft_set_catchall_flush in net/netfilter/nf_tables_api.c in the Linux Kernel. This issue may allow a local attacker to cause double-deactivations of catchall elements, which can result in a memory leak.

Affected products

Debian Linux: 12.0
Linux kernel: before 6.5; 6.5-rc1, 6.5-rc2, 6.5-rc3, 6.5-rc4, 6.5-rc5, 6.5-rc6 — fixed in 6.5
Red Hat Enterprise Linux: 8.0, 9.0

How to fix

Upgrade to a fixed version: Linux kernel 6.5. Check the vendor advisory for mitigations.

References

https://access.redhat.com/security/cve/CVE-2023-4569
https://bugzilla.redhat.com/show_bug.cgi?id=2235470
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20230812110526.49808-1-fw@strlen.de/
https://www.debian.org/security/2023/dsa-5492
https://access.redhat.com/security/cve/CVE-2023-4569
https://bugzilla.redhat.com/show_bug.cgi?id=2235470
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20230812110526.49808-1-fw@strlen.de/
https://www.debian.org/security/2023/dsa-5492

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