---
id: 4338
title: "Reverse engineering of Apple's iOS 0-click CVE-2025-43300: 2 bytes that make size matter"
cve: CVE-2025-43300
cvss: 10
severity: critical
source_domain: blog.quarkslab.com
source_url: "https://blog.quarkslab.com/patch-analysis-of-Apple-iOS-CVE-2025-43300.html"
published_at: "2025-09-03 22:00"
tags: ["reverse-engineering", "ios", "apple", "cve-2025-43300", "imageio", "zero-click"]
phying_url: "https://phying.com/item/4338"
lang: en
---

# Reverse engineering of Apple's iOS 0-click CVE-2025-43300: 2 bytes that make size matter

## Summary

Quarkslab's root-cause analysis of CVE-2025-43300, the iOS ImageIO out-of-bounds write exploited in zero-click campaigns; patch diffing points to RawCamera and DNG parsing.

## Intelligence Metadata

- **Sources:** blog.quarkslab.com
- **CVE:** CVE-2025-43300
- **CVSS:** 10
- **Published:** 2025-09-03 22:00
- **Original:** https://blog.quarkslab.com/patch-analysis-of-Apple-iOS-CVE-2025-43300.html
- **Phying News:** https://phying.com/item/4338