For this recitation, you’ll be reading “SoK: Eternal War in Memory (PDF)” by Lazlo Szekeres, Mathia Payer, Tao Wei, and Dawn Song. This paper describes a variety of memory corruption bugs, and potential solutions. Don’t worry about memorizing every single type of attack described in this paper; aim to understand what makes these attacks possible, and the general ideas behind the solutions.
(We’ve also written a quick guide (PDF) to some of the memory corruption bugs described in the paper, which you might want to take a look at before you start reading.)
The paper is fairly well organized:
- Section I gives you an introduction to the general problem, and a brief history of memory corruption attacks and defenses.
- Section II details many different types of memory corruption attacks. Figure 1 is particularly helpful in organizing these attacks and their defenses. As stated above, don’t worry about memorizing every single type of attack described in this section; aim to understand what makes the various attacks different from one another, as well as what makes each of these possible in the first place.
- Section III describes two currently-deployed defenses, and their drawbacks.
- Section IV outlines some properties and requirements for defenses against memory corruption bugs; those defenses are discussed in Sections V-VIII (each section is a different category of defense).
- Sections IX and X conclude.
As you read, think about the following:
- Stack canaries (or cookies) and ASLR are both widely-deployed. What is good about those solutions? What attacks do they prevent? What attacks don’t they prevent?
- Many of the proposed solutions worsen performance. Are we at a point where these performance hits are outweighed by security concerns?
Questions for Recitation
Before you come to this recitation, write up (on paper) a brief answer to the following (really—we don’t need more than a couple sentences for each question).
Your answers to these questions should be in your own words, not direct quotations from the paper.
- What do the authors mean by “the eternal war in memory”?
- How has this war progressed over time? (i.e., how have attacks and solutions evolved)
- Why hasn’t the war ended?
As always, there are multiple correct answers for each of these questions.