PDF has been an entry point since forever, it is extremely complex and can in some cases even run javascript, it has a huge attack surface.

Too huge attack surface. Good candidate for victim trust (who would not open a pdf file on an iPhone?).

So pdf and images are the best vector for iPhones.

Once you escape the parser you have to reach and escape the sandbox and from there reach the kernel.

If it wasn't PDF it'd be something else. It's everything after the PDF that's alarming here - how did they break out of the app sandbox?

I wonder if pdf.js would be more secure since it runs inside a webpage and can benefit from the browser sandboxing. Though I guess iOS has generally managed to keep most of its apps native rather than web app wrappers (as has happened on Windows).

Well it was TIFF one time

Never mind - that only applied to origins PDF 1.x.

Does Lockdown block all PDFs?

pdf is the new swf

Maybe with LLMs a full rewrite that’s more secure could be done