‘Hacker discovers Adobe PDF Back Doors’

Comments:

• John Mark Ockerbloom says:

  September 16, 2006 at 12:44 pm

  Until more detailed analysis comes in, I’ll withhold judgment on how serious the vulnerability is for the current PDF and Adobe products, but it does show that allowing arbitrary executable code in a document format (whether Javascript in a PDF or arbitrary Java in some proposed ebook formats or DRM schemes) makes all kinds of exploits possible, and it is very difficult to make sure you’re got all the possible holes plugged– especially since many vulnerablites come from the interaction of executable features.

  In particular, if the code can retrieve sensitive information from your local system, *and* can also access arbitrary URLs, then those two features put together potentiallly allow strangers to access sensitive linformation from your local system. (Asking permission to access the URL gives only limited protection;the sensitive information may get obfuscated in a URL or form parameter whose significance is not readily apparent to a user.)

  Which just goes to show that format designers should think very carefully before adding scripting or other executable-code features in their formats, and readers of electronic content should think carefully before allowing content in such formats on their systems.
• David Rothman says:

  September 16, 2006 at 2:43 pm

  John, thanks for the informative and restrained comments. We’ll wish Adobe and others the best of luck in getting to the bottom of this. Of course, security considerations should be very much on the minds of all e-book format designers—and standards-setters. I’d prefer that the vetting happen from outside the vendor community, or at least with the participation of disinterested experts, not just the usual suspects. Meanwhile I hope you’ll keep us up to date as more facts come out. Thanks again. – David
• Bill Janssen says:

  September 19, 2006 at 2:51 am

  Kind of amusing, considering that the forerunner of PDF was Postscript, which was a fully executable language. I think the vulnerabilities (if any) are in Adobe Reader, not PDF.
• David Rothman says:

  September 19, 2006 at 4:06 am

  “…in Adobe Reader, not PDF.”

  But they might as well be the same if you want to read DRMed PDF of the kind that the big publishers favor Great illustration of the need to separate formats from readers!

  David
• Bill Janssen says:

  September 20, 2006 at 3:58 pm

  they might as well be the same if you want to read DRMed PDF of the kind that the big publishers favor.

  Does anyone really want to read EBX-DRM’d PDF (or play any-DRM’d music)? Don’t let anecdotal evidence from that small band of early adopters who bought into the failed 1998 idea of what an ebook would be, and have so far refused to recognize that the future didn’t actually turn out that way, mislead you into thinking that EBX-DRM’d PDF is a signficant fraction of the PDF-reading whole.

  In a very real way, the PDF format is already separated from any particular reader. I’m sure Adobe wishes it weren’t so, but it is.