CVE-2023-4623

2023-09-0614:15:12

CWE-416

[email protected]

web.nvd.nist.gov

465

cve-2023-4623

linux kernel

net/sched

sch_hfsc

use-after-free vulnerability

local privilege escalation

nvd

security advisory

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

7.7

Confidence

High

EPSS

Percentile

5.1%

JSON

A use-after-free vulnerability in the Linux kernel’s net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.

If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.

We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.

Affected configurations

Vulners

NVD

Node

linuxlinux_kernelRange2.6.12–6.6

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "vendor": "Linux",
    "product": "Kernel",
    "packageName": "kernel",
    "repo": "https://git.kernel.org",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.12",
        "lessThan": "6.6",
        "versionType": "custom"
      }
    ],
    "defaultStatus": "unaffected"
  }
]