Billy-Ellis

Billy-Ellis / exr-imageio-poc

Public

PoC for an integer overflow vulnerability in ImageIO patched in iOS/macOS 26.5

19
4
69% credibility
Found May 28, 2026 at 19 stars -- GitGems finds repos before they trend. Get early access to the next one.
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AI Analysis
Python
AI Summary

This project is a proof-of-concept demonstration created by security researchers to illustrate a memory safety bug in Apple's image processing system. It generates a specially crafted image file that exploits an integer overflow vulnerability in how the system calculates buffer sizes when reading EXR format images. When opened on vulnerable versions of iOS/macOS (prior to 26.5), the malformed image causes the program to allocate too little memory and crash. The project serves as educational material for understanding this type of security flaw and helps security teams verify that fixes work correctly.

How It Works

1
🔍 Discovering the Proof of Concept

A security researcher shares a demonstration of a vulnerability found in Apple's image handling system.

2
📄 Understanding the EXR File Format

The tool creates a specially crafted image file that exploits how the system calculates memory needs.

3
⚠️ The Integer Overflow Trick

By setting specific image dimensions, the system mistakenly thinks it needs almost no memory when it actually needs a lot.

4
💥 Memory Gets Overwritten

The tiny memory allocation gets filled with more image data than it can hold, causing the program to crash.

5
🔧 Running the Generator

You execute the Python script which produces a test image file that demonstrates the vulnerability.

✅ Vulnerability Confirmed

The crash proves the bug exists, allowing security teams to develop and test a fix for Apple devices.

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Star Growth

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AI-Generated Review

What is exr-imageio-poc?

This is a Python proof-of-concept that generates a malformed EXR image file to trigger a patched integer overflow in Apple's ImageIO framework. The vulnerability existed in how ImageIO calculated buffer sizes when parsing EXR files -- when width multiplied by height wrapped around to zero, the subsequent malloc would allocate a tiny buffer while the code expected much more space, causing heap corruption. The script crafts an EXR with specific dimensions that trigger this wraparound, demonstrating the memory corruption that follows. This was patched in iOS/macOS 26.5.

Why is it gaining traction?

Security researchers and developers are paying attention because this shows a real-world integer overflow pattern in Apple's widely-deployed image handling code. The project links to a full technical write-up at Zygosec for those who want deeper analysis. For anyone building image parsers or auditing code for similar vulnerabilities, this serves as a concrete example of how a seemingly harmless calculation error can lead to exploitable memory corruption.

Who should use this?

This is strictly for security researchers, vulnerability analysts, and developers studying exploit patterns. If you're building image processing libraries, auditing code for integer handling bugs, or doing bug bounty research on Apple products, this gives you a reproducible test case. It's not a tool for production development -- it's educational material for understanding the vulnerability class.

Verdict

Use this to learn, not to deploy. The 19 stars and 0.699999988079071% credibility score reflect a niche security research tool, not a production library. If you're studying vulnerability patterns or auditing similar code, the PoC and linked write-up are valuable resources. For everyone else, this is a reminder to audit your own integer arithmetic in memory allocation paths.

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