2.8.10 Classes of security problems

Abuse of privilege

If the superuser is evil, then we're all in trouble - nothing can be done

Imposter

Break into system by pretending to be someone else.

For example in Unix, can set up a .rhosts file to allow logins from one machine to another, without having to retype password

Also allows rsh - command to do an operation on a remote node.

Combination means: send rsh request, pretending to be from the trusted user to install a .rhosts file granting imposter full access.

Similarly, if have open X windows connectionover the network, can send message appearing to be key strokes from window but really is commands to allow imposter access. If no encryption, no way to stop this

Trojan Horse

Greeks present Troy with present of wooden horse, but army hidden inside.

Trojan Horse appears helpful, but really does something harmful

Salami Attack

Richard Prior in Superman 3

Idea was to build up a small bit at a time. What happens to partial pennies from interest on bank and mortgage accounts?

Bank keeps it. Re-program so that partial pennies go to programmers account. Millions of customers adds up quickly. See Internet Worm later...

Eavesdropping

Listener - tap into serial line on back of terminal or onto Ethernet. See everything typed in, as almost everything goes over network unencrypted. On telnet, password goes over network unencrypted.

How can these be prevented? Hard to build system that is both useful and prevents misuse.