Use After Free Affecting kernel-libbpf-static package, versions <0:6.1.49-69.116.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-AMZN2023-KERNELLIBBPFSTATIC-5927553
  • published4 Oct 2023
  • disclosed6 Sept 2023

Introduced: 6 Sep 2023

CVE-2023-4208  (opens in a new tab)
CWE-416  (opens in a new tab)
First added by Snyk

How to fix?

Upgrade Amazon-Linux:2023 kernel-libbpf-static to version 0:6.1.49-69.116.amzn2023 or higher.
This issue was patched in ALAS2023-2023-330.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-libbpf-static package and not the kernel-libbpf-static package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation.

When u32_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81.

CVSS Scores

version 3.1