CVE-2023-2163
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | 8.8 | 10 |
| Attack Vector | Local | Local | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | High | Low | None |
| User Interaction | None | None | None |
| Scope | Changed | Changed | Changed |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Red Hat CVSS v3 Score Explanation
On RHEL Kernel, This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.
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