Use After Free Affecting kernel-rt-modules package, versions <0:4.18.0-513.5.1.rt7.307.el8_9


Severity

Recommended
0.0
high
0
10

Based on CentOS security rating

    Threat Intelligence

    EPSS
    0.04% (6th percentile)

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  • Snyk ID SNYK-CENTOS8-KERNELRTMODULES-5890137
  • published 7 Sep 2023
  • disclosed 29 Jul 2023

How to fix?

Upgrade Centos:8 kernel-rt-modules to version 0:4.18.0-513.5.1.rt7.307.el8_9 or higher.

NVD Description

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

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

When route4_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 b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8.

CVSS Scores

version 3.1
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NVD

7.8 high
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    High
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Red Hat

7.8 high