Use After Free Affecting torvalds/linux package, versions [,6.6-rc1)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.01% (2nd percentile)

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  • Snyk IDSNYK-UNMANAGED-TORVALDSLINUX-6026541
  • published22 Oct 2023
  • disclosed5 Sept 2023
  • creditUnknown

Introduced: 5 Sep 2023

CVE-2023-4921  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade torvalds/linux to version 6.6-rc1 or higher.

Overview

Affected versions of this package are vulnerable to Use After Free in the sch_qfq network scheduler, an attacker can achieve local privilege escalation by exploiting a use-after-free condition. This occurs when the plug qdisc is used as a class of the qfq qdisc, and sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). This is only exploitable if the affected module sch_qfq is loaded onto the system.

CVSS Base Scores

version 3.1