CVE-2023-2163

An incorrect verifier pruning flaw was found in BPF in the Linux Kernel that may lead to unsafe code paths incorrectly marked as safe, resulting in arbitrary read/writes in kernel memory, lateral privilege escalation, and container escape.

The Red Hat Enterprise Linux 9.3 not affected, because the required patch applied before this CVE creation. For the Red Hat Enterprise Linux 9 before version 9.3 required fixes applied too.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.

For Red Hat Enterprise Linux 8 to confirm the current state, inspect the sysctl with the command:

cat /proc/sys/kernel/unprivileged_bpf_disabled

The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.