CVE-2022-2586: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-2586 is a vulnerability discovered in the netfilter subsystem of the Linux kernel where a nft object or expression could reference a nft set on a different nft table, leading to a use-after-free vulnerability once that table was deleted. The vulnerability was discovered by Team Orca of Sea Security (@seasecresponse) working with Trend Micro's Zero Day Initiative and was reported as ZDI-CAN-17470. The bug was introduced by commit 958bee14d071 in Linux kernel v3.16-rc1 (Openwall).

The vulnerability exists within the handling of nftobjects, specifically due to the lack of validating the existence of an object prior to performing operations on the object. The issue has a CVSS score of 8.8 (AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H). Exploiting this vulnerability requires CAPNET_ADMIN capability in any user or network namespace (ZDI Advisory).

A local attacker could use this vulnerability to cause a denial of service (system crash) or execute arbitrary code with root privileges. The vulnerability allows attackers to escalate privileges on affected installations of the Linux Kernel (Ubuntu Security, ZDI Advisory).

Fixes for this vulnerability have been released through kernel updates. Various Linux distributions have provided patched versions, including Ubuntu which has released fixes for multiple kernel versions across different releases. For example, Ubuntu 22.04 LTS users should update to linux-image-5.15.0-46-generic version 5.15.0-46.49 or later (Ubuntu Security).