Overview of Computer Vulnerabilities

This document does a pretty good job of covering several basic types of computer vulnerabilities.

http://www.ussrback.com/docs/papers/general/compvuln_draft.pdf

Ignore the date, the information is still relevant.

Headings include:

Anatomy of a Vulnerability
Logic Errors
Social Engineering
Computer Weakness
Policy Oversights
Fault
Severity
Tactics
Authentication
Consequence