Outline for November 24, 2003

Reading: Chapter 22.3-22.5

Discussion Problem

The program sendmail is a message transport agent; that is, it moves mail from one host to another. It also logs each use in the syslog file. One day, I observed the following entries:

Oct 28 06:14:15 nob sendmail[18680]: GAA18680: /bin/sed... Cannot mail directly to files
Oct 28 06:14:52 nob sendmail[18682]: GAA18681: to=<decode>, from=</dev/null>, delay=00:00:44, mailer=prog, stat=Sent
  1. What is suspicious about the first syslog entry? What do you think the author of the first mail message was trying to do? Did it work?
  2. The decode address passes a message to the uudecode(1) program. This program transforms the letter into a file, and puts it into the file system where the mail message says. What does the second message indicate?
  3. What fundamental problem underlies both of these mail messages?

Outline for the Day

  1. Malicious logic
    1. Quickly review Trojan horses, viruses, bacteria; include animal and Thompson's compiler trick
    2. Logic Bombs, Worms (Schoch and Hupp)

Here is a PDF version of this document.