Date: Sat, 20 Mar 1999 02:21:35 -0500 From: whiz To: BUGTRAQ@netspace.org Subject: Eudora Attachment Buffer Overflow I have found another problem with Eudora, attachments, and long filenames that is similar to the the problem I found last year. If two messages are sent to an Eudora 4.1 user that have an attachment with a filename of around 231 or more, the next time the user checkes his mail Eudora crashes. I say 231 because C:\Program Files\Eudora\Attach\ is 31 characters + 231 = 262 = longer then Windows can handle. Eudora trucates the long filename correctly and thats why you cant't send just one messages with a long name, like you use to be able to do with Eudora 4.0. But it truncates it so the the path length is 259 characters which is the maximum. Then when it receives the second attachment it truncates, and trys to add a 1 to the end, this is where it crashes. This allows you to modify the return address to point to arbitrary code. Here is how i tested: Send message to myself with attchment that has a long filename Resend exact message Check my mail Eudora crashes Both the Win 95 and Win NT versions, along with the 4.2 beta of Eudora are affected. The vendor of Eudora, Qualcomm was notified of this problem on 3/12/99. -whiz whiz@enext.dyndns.org http://enext.dyndns.org/~whiz/