PDF is an executable file. Many people are worried about running Javascript but still use PDF files without problems.
Radars would show up with PDFs attached, "Preview Does Not Display 3D Image in PDF Like Acrobat" or similar. And I would feel so ... inadequate.
PDFKit could render and capture basic annotations ... and that was about it. We could show you forms, allow editing, but if the PDF had Javascript that would add two fields and put the sum in a third field I had to shrug and say, "Oh well." The effort of hoisting a JavaScript interpreter/runtime was beyond my skillset anyway.
But then I kind of came to see our subset of PDF support as a kind of feature. It's true, we left out the kitchen sink. Adobe was/is clearly interested in putting everything into PDF.
And I mean, as pointed out here, at least you could open a PDF in Preview and not worry about any Javascript executing. ;-)
For all of the PDFs I've ever encountered, Preview has been sufficient and capable. Thank you for your hard work!
Seconded. At least most pleasant to use for most things, and never balked at anything I needed to see, fortunately.
I met one of the engineers from Adobe and said as much — as politely as I could. He said, yeah, we're modeling our UI on Office.
I saw in an instant that they wanted to be seen as a peer, a co-tool, to the Microsoft suite and it all made sense to me.
Adobe has an awful track record of security (how many exploits in the past 25 years were in Acrobat (not the PDF spec, the actual Acrobat software) and in Flash?) but PDF is an amazing gift to the world, and, thanks to people like you, effectively safer than how Adobe designed it :))
Unfortunately I have the full Acrobat on my work computer, mandated by my employer, sigh, but that's another story.
Formats are on a gradient between "completely code" and "completely data" and PDFs are quite close to the "completely code" extreme'; I guess this is what the parent meant.
And row hammer, to breach the sandbox.
While that may technically be "escaping the sandbox" it's a different case, because it was never meant to work, will be fixed and often is fixed.
Sure if the PDF standard exposed a "globalThis.runBlobAsNativeExecutable" function it would be worse, but it is still escaping the sandbox.
It is worth noting that Chromium and later Firefox both added PDF viewers that live inside the browser sandbox. They are essentially web-apps that render the PDF. When I worked at Google they strongly recommended using Chrome for opening PDF files because they felt much more comfortable about its security and sandboxing than other PDF readers.
On another perspective is that you are likely browsing the internet anyways. In fact you likely got the PDF by visiting a website. So you have already exposed a huge attack surface (your browser) to a possible hostile adversary. It is better to expose them to the same attack surface again (plus whatever security the PDF reader itself provides) than to give them a fresh new attack surface.