---
id: CVE-2021-33655
title: >-
  When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel
  will write memory out of bounds.
summary: >-
  When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel
  will write memory out of bounds.
severity: medium
cvss: 6.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-787
  - CWE-787
vendor: linux
product: linux_kernel
affected:
  - linux_kernel < 5.19
  - linux_kernel = 5.19
  - debian_linux = 10.0
  - debian_linux = 11.0
patched:
  - linux_kernel 5.19
published: '2022-07-18'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T12:17:12.710'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-33655'
references:
  - url: 'http://www.openwall.com/lists/oss-security/2022/07/19/2'
    label: securities@openeuler.org
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=086ff84617185393a0bbf25830c4f36412a7d3f4
    label: securities@openeuler.org
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html'
    label: securities@openeuler.org
  - url: 'https://www.debian.org/security/2022/dsa-5191'
    label: securities@openeuler.org
  - url: 'http://www.openwall.com/lists/oss-security/2022/07/19/2'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=086ff84617185393a0bbf25830c4f36412a7d3f4
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2022/dsa-5191'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-794697.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.00315
epssPercentile: 0.22664
ingestedAt: '2026-10-14T12:29:10.829Z'
---

## Overview

When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of bounds.

## Affected

- `linux_kernel < 5.19`
- `linux_kernel = 5.19`
- `debian_linux = 10.0`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.19`