CVE-2022-32250

El archivo net/netfilter/nf_tables_api.c en el kernel de Linux versiones hasta 5.18.1, permite a un usuario local (capaz de crear espacios de nombres de usuario/red) escalar privilegios a root porque una comprobación incorrecta de NFT_STATEFUL_EXPR conlleva a un uso de memoria previamente liberada

A use-after-free vulnerability was found in the Linux kernel's Netfilter subsystem in net/netfilter/nf_tables_api.c. This flaw allows a local attacker with user access to cause a privilege escalation issue.

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the nf_tables_expr_destroy method. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.