CVE-2023-53619: linux kernel Use-After-Free — Fix

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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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	3.6 — 4.14.322
linux	linux_kernel	4.15 — 4.19.291
linux	linux_kernel	4.20 — 5.4.251
linux	linux_kernel	5.5 — 5.10.188
linux	linux_kernel	5.11 — 5.15.121
linux	linux_kernel	5.16 — 6.1.39
linux	linux_kernel	6.2 — 6.4.4
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/00716f25f9697d02a0d9bd622575c7c7321ba3d0 https://git.kernel.org/stable/c/05561f822f27b9fa88fa5504ddec34bf38833034 https://git.kernel.org/stable/c/4ee69c91cb8f9ca144bc0861969e5a1a3c6152a7 https://git.kernel.org/stable/c/61c7a5256543ae7d24cd9d21853d514c8632e1e9 https://git.kernel.org/stable/c/6eef7a2b933885a17679eb8ed0796ddf0ee5309b https://git.kernel.org/stable/c/6f03ce2f1abcb9f9d0511e3659ca6eb60e39f566 https://git.kernel.org/stable/c/8289d422f5e484efe4a565fe18e862ecd621c175 https://git.kernel.org/stable/c/fce5cc7cbd4b92f979bf02c9ec5fb69aaeba92d7

Frequently Asked Questions

What is CVE-2023-53619? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-53619? +

CVE-2023-53619 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-53619? +

CVE-2023-53619 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-53619? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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