Richard Bejtlich said
I read six books on software security recently, namely "Writing Secure Code, 2nd Ed" by Michael Howard and David LeBlanc; "19 Deadly Sins of Software Security" by Michael Howard, David LeBlanc, and John Viega; "Software Security" by Gary McGraw; "The Security Development Lifecycle" by Michael Howard and Steve Lipner; "High-Assurance Design" by Cliff Berg; and "Security Patterns" by Markus Schumacher, et al. Each book takes a different approach to the software security problem, although the first two focus on coding bugs and flaws; the second two examine development processes; and the last two discuss practices or patterns for improved design and implementation. My favorite of the six is Gary McGraw's, thanks to his clear thinking and logical analysis. The other five are still noteworthy books. All six will contribute to the production of more security software.
"Security Development Lifecycle" (SDL) is unique because in many ways it exposes the guts of Microsoft's product development process. I cannot recall seeing another technical company share so much of its internal procedures with the public. One of the most interesting aspects of SDL is the attention paid to security after a product is shipped. No one at Microsoft breathes a sigh of relief when boxes appear on store shelves. Instead, Microsoft explains how it conducts security response planning in ch 15 and security response execution in ch 17. (Between the two is ch 16 -- only 3/4 of a page! Why bother?)
Although I liked SDL overall (enough to justify 4 stars), I thought it suffered three major problems. First, I don't think the audience was defined properly. p xviii mentions "managers" as the primary target, along with architects and designers. Specifically, "this is not a book for developers." Yet, ch 12 ("Secure Testing Policies") is definitely for programmers. A manager probably not going to know what a "null pointer dereference" is; at the very least that is not a subject that should be discussed in a book for managers.
Second, I think SDL suffers a little too much overlap with the earlier Microsoft book "Writing Secure Code, 2nd Ed." WSC2E addressed writing documentation, security testing ,and obviously secure coding in much the same language as repeated in SDL. Sometimes repetition is justified, but perhaps those subjects appeared in WSC2E for a reason and did not belong in a book for managers.
Third, and most importantly, Microsoft continues its pattern of misusing terms like "threat" that started with "Threat Modeling" and WSC2E. SDL demonstrates some movement on the part of the book's authors towards more acceptable usage, however. Material previously discussed in a "Threat Modeling" chapter in WSC2E now appears in a chapter called "Risk Analysis" (ch 9) -- but within the chapter, the terms are mostly still corrupted. Many times Microsoft misuses the term risk too. For example, p 94 says "The Security Risk Assessment is used to determine the system's level of vulnerability to attack." If you're making that decision, it's a vulnerability assessment; when you incorporate threat and asset value calculations with vulnerabilities, that's true risk assessment.
The authors try to deflect what I expect was criticism of their term misuse in previous books. On p 102 they say "The meaning of the word threat is much debated. In this book, a threat is defined as an attacker's objective." The problem with this definition is that it exposes the problems with their terminology. The authors make me cringe when I read phrases like "threats to the system ranked by risk" (p 103) or "spoofing threats risk ranking." On p 104, they are really talking about vulnerabilities when they write "All threats are uncovered through the analysis process." The one time they do use threat properly, it shows their definition is nonsensical: "consider the insider-threat scenario -- should your product protect against attackers who work for your company?" If you recognize that a threat is a party with the capabilities and intentions to exploit a vulnerability in an asset, then Microsoft is describing insiders appropriately -- but not as "an attacker's objective."
Don't get me wrong -- there's a lot to like about SDL. I gave the book four stars, and I think it would be good to read it. I fear, though, that this is another book distributed to Microsoft developers and managers riddled with sometimes confusing or outright wrong ways to think about security. This produces lasting problems that degrade the community's ability to discuss and solve software security problems. I also question the implication that SDL is great and everything else doesn't produce verified security improvements. I can understand denigrating Linux, but is Microsoft afraid to acknowledge the security record of an OS like OpenBSD?
W. Conklin said
This book is a wonderful glimpse behind the curtain at one of the most advanced software development firms in the world. Renowned for hiring the best and the brightest, this book shows how they learned to do development in a smarter and more efficient manner. Some people may consider a SDL to be overkill, but the evidence presented is clear; if you want an efficient, effective process for meeting customer requirements, one must consider and address security. And this book is the how-to companion to the other great titles associated with Microsoft and secure coding. Whereas Writing Secure Code, Second Edition, focuses on technical detail, this book focuses on the process that enables developer to achieve the technical details.
This book is the project manager's guide to how it should be done. How to set up your development processes so that better developers can contribute in an effective fashion towards making better software. For some, there are no new secrets revealed in this book, but I know of no other source with all this information together in one place. And it comes with a bonus - the material has been tested and proven at the world's largest developer group. And in this case, bigger is not easier, but much harder - decentralized bureaucracies and business unit independence aside, it works at Microsoft, and as it gets further embedded into their processes and systems, the future for this methodology looks better and better.
Thank you Mike Howard and Steve Lipner for finishing the story. First we learn what to do (Writing Secure Code), now you let us know how to get it done (The Security Development Lifecycle). This may not be the perfect book, but then, I've yet to see that one. This book does advance the management side of the state-of-the-art light years forward, into the current century. This book is the textbook for the process side of software engineering in my classes, and I look forward to future editions and more details from behind the curtain.
John Matlock said
As is well known, Microsoft software has been known in the past for producing software that had numerous problems in the security area. It finally became so obvious that the company was forced to make a major change in emphasis regarding the security holes in their products.
Microsoft is, of course, a huge software development organization. To move the organization into writing more secure code it was necessary to develop plans, procedures, classes for managers and programmer and the like to implement writing more secure code. The resulting effort is called the Security Development Lifecycle (SDL).
The results of implementing SDL are summarized in the Introduction to the book. Here are two newspaper headlines quoted there:
Gartner Recommends Against Microsoft IIS (eWeek, 2001)
We actually consider Microsoft to be leading the software industry now in improvements in their security development life cycle (CRN 2006)
This book is aimed at the people managing and defining software projects. It does not contain very many specific code examples that would appeal to the developer. This is not to say that developers shouldn't read it, but that it is not a detailed techie document.
The CD that comes with the book includes several documents that extend the concepts talked about in the book and a six part security class video conducted by the authors.
One note of caution. This book is on the Microsoft approach to security. It's what they are doing. It works for them. But there are also other approaches such as that being implemented by organizations such as the US Government.
Alexander T. Barclay said
I have been very impressed with other offerings from the Microsoft professional series and was excited when this book was released. This is not a technical book like "Writing Secure Code" and "Code Complete" but a book aimed at managers responsible for software projects. My opinion is not based on real world experience of large software projects, but on academic projects smaller in scale than those of Microsoft.
The introductory material is weak, part 1 which explores the reasoning and history behind the SLD seemed to be stretched needlessly, repeating the same information multiple times. Chapter 4 which provides the management impact of the SDL lacks focus, and does not justify the need (ROI) for the SDL.
Part 2 goes though each step of the SDL in detail. Overall, this section is more polished and for the most part does a good job of covering each domain in detail. While this book is focused on managerial and operational activities, there are times where it awkwardly delves into specific technical details. Chapter 10 (Documents, Tools, Practices for customers) and chapter 15 (Response planning) are strong chapters which most everyone can lean from.
Part 3 is a series of reference materials. Chapter 20 (Crypto) and 21 (Compiler Options) are good guidelines to compare your organizations own practices against.
Strengths:
+ Talks about a real methodology being used at MS everyday
+ Excellent references, cites many foundation papers
+ Gives the reasoning behind many decisions in development in SDL
+ Good discussion of threat trees
+ Managerial focused chapters are well thought out and complete
Weaknesses:
- Technical information is MS focused
- Might be acronym heavy for non-technical/security managers
- Does not reference other secure development processes, such as IATF section 3
- Does not reference NIST 800 series for risk analysis
What I would like to see:
*Expanded Chapter 5 (Education and Awareness), giving more information on the curriculum of security classes offered.
*Better balance between the technical and managerial aspects of the SDL. This book would be stellar either with more technical information (platform independent) or by focusing the book more on managerial aspects of the SDL.
*The actual SDL documents being used at MS
Overall, this is a good book, I would recommend it. However I do think a second edition would help this book immensely.
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