Use After Free Affecting bpftool package, versions <0:4.18.0-513.5.1.el8_9


Severity

Recommended
0.0
high
0
10

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.04% (5th percentile)

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  • Snyk IDSNYK-ALMALINUX8-BPFTOOL-6090445
  • published27 Nov 2023
  • disclosed14 Nov 2023

Introduced: 14 Nov 2023

CVE-2023-4207  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 bpftool to version 0:4.18.0-513.5.1.el8_9 or higher.
This issue was patched in ALSA-2023:7077.

NVD Description

Note: Versions mentioned in the description apply only to the upstream bpftool package and not the bpftool package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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

When fw_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 76e42ae831991c828cffa8c37736ebfb831ad5ec.

CVSS Scores

version 3.1