CVE-2023-3776 Use-after-free in Linux kernel's net/sched: cls_fw component

2023-07-2120:49:53

CWE-416

Google

www.cve.org

linux kernel

use-after-free

net/sched

cls_fw

local privilege escalation

reference counter

tcf_change_indev

fw_set_parms

tcf_bind_filter

upgrading

vulnerability

7.8 High

CVSS3

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

7.9 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.

CNA Affected

[
  {
    "defaultStatus": "unaffected",
    "packageName": "kernel",
    "product": "Kernel",
    "repo": "https://git.kernel.org",
    "vendor": "Linux",
    "versions": [
      {
        "lessThan": "6.5",
        "status": "affected",
        "version": "2.6",
        "versionType": "custom"
      }
    ]
  }
]