CVE-2025-24201 WebKit Vulnerability Detector (PoC)

This proof-of-concept detects whether a WebKit-based browser is vulnerable to CVE‑2025‑24201, a high-severity out-of-bounds write vulnerability caused by incorrect capability validation in the WebGL implementation.

🔍 Vulnerability Summary

CVE‑2025‑24201 is triggered when a WebGLRenderingContext (WebGL 1) allows enabling the constant PRIMITIVE_RESTART_FIXED_INDEX (0x8D69) — a capability only valid in WebGL 2 — without generating a GL_INVALID_OPERATION or GL_INVALID_ENUM error.

This misbehavior can lead to memory corruption during draw calls involving index buffers.

✅ What This Test Does

The PoC:

1. Creates a WebGL 1 context via canvas.getContext("webgl").
2. Attempts to enable the capability 0x8D69.
3. Checks the return value of gl.getError().

If no error is returned, the implementation is likely vulnerable.

📄 Files

• index.html – The standalone HTML file that performs the detection and prints result + internal log to screen.
• README.md – This file.

🧪 Usage

Simply open the index.html file in the browser you want to test.

Expected results:

• 🛡️ Safe – error returned → Not vulnerable
• ✅ VULNERABLE – no error on gl.enable(0x8D69) → Vulnerable

⚠️ Notes

• This is a non-crashing PoC. It does not attempt to trigger memory corruption, only detects exposure.
• The detection relies on GL behavior and will not trigger on patched WebKit versions (after March 2025).

📚 References

• CVE‑2025‑24201 – NVD
• WebKit Bug 285858 (patch)
• Apple Security Update – March 2025

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