That's not my experience. I believe there are many design problems you can find more quickly and, more importantly, accurately by using the code. I find this to be true even when there is a documented design -- but there's no question in the case where all you have is code.
In fact, if the design isn't fairly obvious in the code, then that's a security problem in itself. Unless it's clear, developers won't understand it and will make more mistakes. Static analysis tools can help a lot here. Used properly, they can provide design-level insight into a software baseline. The huge advantage is that it's correct. --Jeff -----Original Message----- From: Gary McGraw [mailto:[EMAIL PROTECTED] Sent: Thursday, February 02, 2006 9:06 PM To: [EMAIL PROTECTED]; Secure Coding Mailing List Subject: RE: [SC-L] Bugs and flaws Not unless you talk to the designer. You might get lucky and find a design problem or two by looking at code, but that usually doesn't work. That's not to say that all systems have adequate documentation about design (not to mention requirements that you correctly cited before)! They don't. When they don't, you have to try to construct them. Doing them from code is very difficult at best. gem -----Original Message----- From: Jeff Williams [mailto:[EMAIL PROTECTED] Sent: Thu Feb 02 20:59:14 2006 To: Gary McGraw; 'Secure Coding Mailing List' Subject: RE: [SC-L] Bugs and flaws Um, so if there is no documentation you can't find design flaws? --Jeff -----Original Message----- From: Gary McGraw [mailto:[EMAIL PROTECTED] Sent: Thursday, February 02, 2006 8:50 PM To: Jeff Williams; Secure Coding Mailing List Subject: RE: [SC-L] Bugs and flaws I'm sorry, but it is just not possible to find design flaws by staring at code. gem -----Original Message----- From: Jeff Williams [mailto:[EMAIL PROTECTED] Sent: Thu Feb 02 20:32:29 2006 To: 'Secure Coding Mailing List' Subject: RE: [SC-L] Bugs and flaws At the risk of piling on here, there's no question that it's critical to consider security problems across the continuum. While we're at it, the analysis should start back even further with the requirements or even the whole system concept. All of the representations across the continuum (rqmts, arch, design, code) are just models of the same thing. They start more abstract and end up as code. A *single* problem could exist in all these models at the same time. Higher-level representations of systems are generally eclipsed by lower level ones fairly rapidly. For example, it's a rare group that updates their design docs as implementation progresses. So once you've got code, the architecture-flaws don't come from architecture documents (which lie). The best place to look for them (if you want truth) is to look in the code. To me, the important thing here is to give software teams good advice about the level of effort they're going to have to put into fixing a problem. If it helps to give a security problem a label to let them know they're going to have to go back to the drawing board, I think saying 'architecture-flaw' or 'design-flaw' is fine. But I agree with others that saying 'flaw' alone doesn't help distinguish it from 'bug' in the minds of most developers or architects. --Jeff Jeff Williams, CEO Aspect Security http://www.aspectsecurity.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Crispin Cowan Sent: Wednesday, February 01, 2006 5:07 PM To: John Steven Cc: Will Kruse; Secure Coding Mailing List Subject: Re: [SC-L] Bugs and flaws John Steven wrote: > I'm not sure there's any value in discussing this minutia further, but here > goes: > We'll let the moderator decide that :) > 1) Crispin, I think you've nailed one thing. The continuum from: > > Architecture --> Design --> Low-level Design --> (to) Implementation > > is a blurry one, and certainly slippery as you move from 'left' to 'right'. > Cool. > But, we all should understand that there's commensurate blur in our analysis > techniques (aka architecture and code review) to assure that as we sweep > over software that we uncover both bugs and architectural flaws. > Also agreed. > 2) Flaws are different in important ways bugs when it comes to presentation, > prioritization, and mitigation. Let's explore by physical analog first. > I disagree with the word usage. To me, "bug" and "flaw" are exactly synonyms. The distinction being drawn here is between "implementation flaws" vs. "design flaws". You are just creating confusing jargon to claim that "flaw" is somehow more abstract than "bug". Flaw ::= defect ::= bug. A vulnerability is a special subset of flaws/defects/bugs that has the property of being exploitable. > I nearly fell through one of my consultant's tables as I leaned on it this > morning. We explored: "Bug or flaw?". > The wording issue aside, at the implementation level you try to code/implement to prevent flaws, by doing things such as using higher quality steel (for bolts) and good coding practices (for software). At the design level, you try to design so as to *mask* flaws by avoiding single points of failure, doing things such as using 2 bolts (for tables) and using access controls to limit privilege escalation (for software). Crispin -- Crispin Cowan, Ph.D. http://crispincowan.com/~crispin/ Director of Software Engineering, Novell http://novell.com Olympic Games: The Bi-Annual Festival of Corruption _______________________________________________ Secure Coding mailing list (SC-L) SC-L@securecoding.org List information, subscriptions, etc - http://krvw.com/mailman/listinfo/sc-l List charter available at - http://www.securecoding.org/list/charter.php _______________________________________________ Secure Coding mailing list (SC-L) SC-L@securecoding.org List information, subscriptions, etc - http://krvw.com/mailman/listinfo/sc-l List charter available at - http://www.securecoding.org/list/charter.php ---------------------------------------------------------------------------- This electronic message transmission contains information that may be confidential or privileged. The information contained herein is intended solely for the recipient and use by any other party is not authorized. If you are not the intended recipient (or otherwise authorized to receive this message by the intended recipient), any disclosure, copying, distribution or use of the contents of the information is prohibited. If you have received this electronic message transmission in error, please contact the sender by reply email and delete all copies of this message. Cigital, Inc. accepts no responsibility for any loss or damage resulting directly or indirectly from the use of this email or its contents. Thank You. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- This electronic message transmission contains information that may be confidential or privileged. The information contained herein is intended solely for the recipient and use by any other party is not authorized. If you are not the intended recipient (or otherwise authorized to receive this message by the intended recipient), any disclosure, copying, distribution or use of the contents of the information is prohibited. If you have received this electronic message transmission in error, please contact the sender by reply email and delete all copies of this message. Cigital, Inc. accepts no responsibility for any loss or damage resulting directly or indirectly from the use of this email or its contents. Thank You. ---------------------------------------------------------------------------- _______________________________________________ Secure Coding mailing list (SC-L) SC-L@securecoding.org List information, subscriptions, etc - http://krvw.com/mailman/listinfo/sc-l List charter available at - http://www.securecoding.org/list/charter.php
