CVE-2022-39190: 
Linux Kernel vulnerability analysis and mitigation

A vulnerability was discovered in net/netfilter/nf_tables_api.c in the Linux kernel before version 5.19.6. The vulnerability (CVE-2022-39190) was reported by Gwangun Jung and disclosed on September 2, 2022. The issue affects the netfilter subsystem in the Linux kernel, specifically related to chain binding functionality (Ubuntu Security).

The vulnerability exists in the nf_tables subsystem where the system does not properly prevent binding to an already bound chain. This flaw was introduced in the netfilter component and was fixed by updating nft_data_init() to report EINVAL if a chain is already bound (Kernel Commit). The vulnerability has been assigned a CVSS 3 Severity Score of 5.5 (Medium) (Ubuntu Security).

When exploited, this vulnerability can lead to a denial of service condition, potentially causing a system crash. The impact is limited to local attacks, requiring the attacker to have local access to the system (Ubuntu Security).

The vulnerability can be exploited by a local attacker who could use this to cause a denial of service by attempting to bind to an already bound chain (Ubuntu Security).

The vulnerability has been fixed in Linux kernel version 5.19.6 and backported to various distributions. For Ubuntu users, the fix has been applied to version 5.15.0-53.59 for Ubuntu 22.04 LTS. A mitigation strategy includes ensuring unprivileged user namespaces are disabled by setting the kernel.unprivileged_userns_clone sysctl to 1, which prevents unprivileged users from loading netfilter rules (Ubuntu Security).