CVE-2023-53619
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-07

Last updated on: 2026-02-05

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: Avoid nf_ct_helper_hash uses after free If nf_conntrack_init_start() fails (for example due to a register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini() clean-up path frees the nf_ct_helper_hash map. When built with NF_CONNTRACK=y, further netfilter modules (e.g: netfilter_conntrack_ftp) can still be loaded and call nf_conntrack_helpers_register(), independently of whether nf_conntrack initialized correctly. This accesses the nf_ct_helper_hash dangling pointer and causes a uaf, possibly leading to random memory corruption. This patch guards nf_conntrack_helper_register() from accessing a freed or uninitialized nf_ct_helper_hash pointer and fixes possible uses-after-free when loading a conntrack module.
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Meta Information
Published
2025-10-07
Last Modified
2026-02-05
Generated
2026-05-07
AI Q&A
2025-10-07
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53619
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.5
linux linux_kernel From 6.2 (inc) to 6.4.4 (inc)
linux kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a use-after-free (UAF) issue in the Linux kernel's netfilter conntrack component. If the initialization function nf_conntrack_init_start() fails, the cleanup function frees a data structure called nf_ct_helper_hash. However, other netfilter modules can still load and attempt to access this freed nf_ct_helper_hash pointer, leading to use-after-free. This can cause random memory corruption. The fix involves adding checks to prevent accessing the freed or uninitialized nf_ct_helper_hash pointer.


How can this vulnerability impact me? :

This vulnerability can lead to random memory corruption in the Linux kernel, which may cause system instability, crashes, or potentially allow an attacker to execute arbitrary code with kernel privileges. This can compromise the security and reliability of systems running vulnerable Linux kernel versions with netfilter conntrack enabled.


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