-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 El 2005-08-29 a las 16:32 +0200, peter.holm escribió:
Gracias Carlos, especialmente por la regla ...... me has dado una idea, el acrobat llama a casa para comprobar si hay versiones mas modernas (al menos eso es lo que dicen ellos),
Esa es sólo una de las comunicaciones posibles. También, insisto, cuando cargas determinados ficheros pdf, estos pueden incluir codigo javascript que se puede ejecutar al cargarlo, al imprimirlo, etc, cuando al autor le de la gana (no es adobe); y entre las cosas que puede hacer está conectarse con el un servidor del autor del documento y decirle que tú, fulano de tal, en tal IP, estás leyendo su documento en tal máquina. Pe: http://lwn.net/Articles/129729/ ... Aquí tienes un par de artículos que comentan el tema: Date: Mon, 18 Apr 2005 14:18:08 +0200 (CEST) From: Michel Messerschmidt Subject: Re: [suse-security] How to block Acroread 7 with SuSE FW2?
Al Bogner wrote: I don't have an answer for you, but am curious about this issue. Do you have further info regarding what and how it 'sends messages home?'
The site http://www.remoteapproach.com/ provides a "service" to track the usage of a PDF document. I haven't seen one of those PDFs myself, but rumours say it is implemented with embedded javascript. The Adobe javascript implementation allows many things users commonly don't expect. The implementation of javascript in PDF somehow reminds me of VBA macros in MS Office: - - it is a powerful programming language - - it is enabled by default - - there is no sufficient security concept - - there are ways to "auto-execute" code in a document (for example just by opening, closing, printing... a document) See http://partners.adobe.com/public/developer/en/pdf/PDFReference16.pdf and http://partners.adobe.com/public/developer/en/acrobat/sdk/pdf/javascript/Acr... for details. Date: Sat, 23 Jul 2005 17:51:48 +0100 (BST) From: ????karsites.net Subject: [suse-security] Acrobat Reader upgrade to 7.0 Acrobat Reader likes to phone home apparently - LOL! Maybe these people are using AJAX technology also? full article at: http://lwn.net/Articles/129729/ Linux users may have been pleased to find that Adobe has finally made available a new version of its Acrobat Reader, with accessibility features, a much slicker interface than Acrobat 5.x and new and other spiffy features. However, there are a few other features that Linux users should be aware of. A company called Remote Approach is promising to alert PDF publishers as to the "reach and use of their materials." We were curious to find out how Remote Approach was going to make good on its promise, given that PDF has largely been seen as a one-way medium. To find out, we created a test account and uploaded a PDF to be "tagged" by Remote Approach, and then downloaded the modified document to see whether Remote Approach could log our use of the document. Remote Approach's reporting did not work when we viewed the document with Kpdf, Xpdf and Adobe Reader 5.0.10. It also failed using Apple's "Preview" application on Mac OS X. The document was still viewable with no apparent glitch in other PDF readers, but the reporting function did not work. However, when we opened the file using Adobe Acrobat Reader 7, Remote Approach started logging views from our IP address. After doing a little research, we found that Adobe's Reader was connecting to http://www.remoteapproach.com/remoteapproach/logging.asp each time we opened the document. The information is submitted over port 80 using HTTP, so it is unlikely that a home or office firewall would, in a normal configuration, block the activity, unless the firewall administrator is attempting to block Web browsing. Apparently, Remote Approach's "tag" to our document included the addition of JavaScript code causing Acrobat to report back to their server; the information reported includes the fact that the document had been read, our IP address, and which viewer it had been read in. (Interestingly, Remote Approach does not seem to recognize the Linux version of Acrobat Reader, as it left the "User Agent" field blank in its reports.) Regards - Keith Roberts - -- Saludos Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFDFZAztTMYHG2NR9URAt9WAJ9fXRVjNz9z3EK+g7xcQ0wshuOmpwCeKtAu nVqzKjPIADPglC6GHcID/tM= =VHfo -----END PGP SIGNATURE-----