The recent LIBPNG vulnerability can be exploited by sending HTML e-mail containing an embedded malicious PNG image referenced locally using cid: as well, if the recipient of the e-mail is using a vulnerable mail client. See
Chris Evans' security advisory http://scary.beasts.org/security/CESA-2004-001.txt Therefore this issue is somewhat serious, and deserves more attention. Mail clients need to block automatic display of all images, not just those referenced by external URL inside an img tag. It is a lot of work to locate vulnerable binary code, notify vendors of vulnerable or flawed products and teach them this remedial basic security principle. I am looking for volunteers who are interested in helping out with this effort. Does anyone have a list of closed-source products known to contain LIBPNG or code derived from it that is believed vulnerable? Most Secure Regards, Jason Coombs Director of Forensic Services PivX Solutions, Inc. [EMAIL PROTECTED] -----Original Message----- From: "CHRIS GRABENSTEIN" <[EMAIL PROTECTED]> Date: Mon, 23 Aug 2004 15:20:39 To:<[EMAIL PROTECTED]> Subject: RE: Images being pulled in Outlook 2003 even though don't download pictures is set? The reference after cid: refers to an image embedded in the email itself. The image arrives as part of the email rather than being pulled from a remote server. -----Original Message----- From: Spencer, Mark [mailto:[EMAIL PROTECTED] Sent: Sunday, August 22, 2004 12:36 PM To: [EMAIL PROTECTED] Subject: Images being pulled in Outlook 2003 even though don't download pictures is set? I've been getting lots of spam with images being displayed, even though my Outlook 2003 is set to not download pictures automatically. Here's what I think is the relevant code (minus < and >): DIV align=center FONT face=Arial size=2 IMG src="cid:kfhyepds_bfjhwcxn_dkiaarqo"; /FONT /DIV /BODY /HTML Any advice on how to deal with this? How does that "cid: .." translate into a legitimate IP address from which to pull an image? Thanks! --------------------------------------------------------------------------- Computer Forensics Training at the InfoSec Institute. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors. Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse so that it never happens again. http://www.securityfocus.com/sponsor/InfoSecInstitute_security-basics_040817 ---------------------------------------------------------------------------- --------------------------------------------------------------------------- Computer Forensics Training at the InfoSec Institute. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors. Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse so that it never happens again. http://www.infosecinstitute.com/courses/computer_forensics_training.html ---------------------------------------------------------------------------- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
