CVE-2023-4921 Use-after-free in Linux kernel's net/sched: sch_qfq component

2023-09-1219:45:19

CWE-416

Google

www.cve.org

linux kernel

net/sched

sch_qfq

use-after-free

vulnerability

local privilege escalation

commit 8fc134fee27f2263988ae38920bc03da416b03d8

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

7.9

Confidence

High

EPSS

Percentile

5.1%

JSON

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

When the plug qdisc is used as a class of the qfq qdisc, 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().

We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.

CNA Affected

[
  {
    "vendor": "Linux",
    "product": "Kernel",
    "packageName": "kernel",
    "repo": "https://git.kernel.org",
    "versions": [
      {
        "status": "affected",
        "version": "3.8",
        "lessThan": "6.6",
        "versionType": "custom"
      }
    ],
    "defaultStatus": "unaffected"
  }
]