CVE-2023-53619: netfilter: conntrack: Avoid nf_ct_helper_hash uses after free
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: Avoid nfcthelperhash uses after free
If nfconntrackinitstart() fails (for example due to a registernfconntrackbpf() failure), the nfconntrackhelperfini() clean-up path frees the nfcthelperhash map.
When built with NFCONNTRACK=y, further netfilter modules (e.g: netfilterconntrackftp) can still be loaded and call nfconntrackhelpersregister(), independently of whether nfconntrack initialized correctly. This accesses the nfcthelperhash dangling pointer and causes a uaf, possibly leading to random memory corruption.
This patch guards nfconntrackhelperregister() from accessing a freed or uninitialized nfcthelperhash pointer and fixes possible uses-after-free when loading a conntrack module.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Ensure the Linux kernel includes the fix titled "netfilter: conntrack: Avoid nf_ct_helper_hash uses after free" so that nf_conntrack_helper_register() is guarded from accessing a freed nf_ct_helper_hash map (this fixes the UAF that can occur when loading a conntrack module after nf_conntrack_init_start() or register_nf_conntrack_bpf() fails).
Linux kernel netfilter conntrack Guard nf_conntrack_helper_register() from accessing freed nf_ct_helper_hash (dangling pointer/UAF fix) = Apply the kernel patch that prevents nf_ct_helper_hash use-after-free during module load after nf_conntrack_init_start() failure
Event History
Frequently Asked Questions
What is the severity of CVE-2023-53619?
CVE-2023-53619 has been classified with a severity level that necessitates attention due to potential exploitation risks in affected Linux kernel versions.
How do I fix CVE-2023-53619?
To mitigate CVE-2023-53619, it is recommended to upgrade to the latest patched version of the Linux kernel that addresses this vulnerability.
Which versions of the Linux kernel are affected by CVE-2023-53619?
CVE-2023-53619 affects multiple versions of the Linux kernel ranging from 3.6 to 6.5-rc1, including specific versions within those ranges.
What type of vulnerability is CVE-2023-53619?
CVE-2023-53619 is a use-after-free vulnerability associated with the connection tracking subsystem in the Linux kernel.
Is there any workaround for CVE-2023-53619?
Currently, the most effective solution for CVE-2023-53619 is to apply the recommended kernel updates as no specific workarounds are provided.