Security Threat Analysis: Interview With Dino A. Dai Zovi

More On Sandboxing

Alan: So things like “sandboxing” are designed to prevent unforeseen vulnerabilities from being transformed into large exploits.

Dino: Yes, as the name suggests, “sandboxing” is meant to contain the spill in the event of a compromise. Sandboxes don’t actually prevent exploits, however. They more prevent those exploits from taking other actions on the system. For example, Google’s Chrome has a very restrictive sandbox for Web rendering processes. And while this won’t prevent an exploit from executing arbitrary code, it will prevent that executing code from harming your system.

Alan: You've really been able to adapt your knowledge from PowerPC era to the Intel-Mac era. With the upcoming Snow Leopard, Apple will be implementing features such as ASLR, code signing for kernel extensions, full NX bit support, and sandboxing for many of the main applications. These are all features currently supported by Vista. How is this going to help secure the Mac? How does "sandboxing" really work when Chrome's first exploit allowed remote applications to be launched from Java, and IE8 was recently exploited at this year's CanSecWest?

Dino: I haven't looked at Snow Leopard yet due to the pre-release NDA, but I am glad to hear that they will be implementing those features.  

Alan: You know actually, as you were saying that, I just realized that I don’t think it’s actually 100% confirmed yet. It’s really just the blogsphere right now. But let’s assume that this is what Snow Leopard will add. How is that going to change things?

Dino: I hope their implementations are sound and I will definitely be buying and installing Snow Leopard on all of my systems from Day One. All of these security features hamper attacks at multiple stages. ASLR and NX make it much more difficult for an exploit to inject or re-purpose code in an application. The sandboxing limits the actions that an application can perform so that even if it does begin running attacker-supplied code, the actions that the attacker may perform will be constrained. Finally, kernel extension code signing prevents attackers from installing new software into the core of the operating system. Attackers often install rootkits into the kernel in order to conceal their attacks and maintain access to compromised systems.

There is a difference between operating system-level and browser-level sandboxing. Chrome is the only Web browser to implement browser-based sandboxing. This is a highly smart move on their part and the main reason that Chrome was not compromised at Pwn2Own this year. The limitation of Chrome's sandbox model, however, is that it cannot sandbox Web browser plugins such as Flash and Java. These plugins need full access to the system, so the sandboxing system used for Web content renderers cannot be used. The Web content rendering processes are highly limited and cannot touch the file system at all. Breaking out of the Chrome renderer process sandbox would be an impressive feat in itself.

Create a new thread in the US Reviews comments forum about this subject
This thread is closed for comments
25 comments
Comment from the forums
    Your comment
  • cruiseoveride
    Wonder why he didnt mention SELinux
  • mrubermonkey
    If it were so easy to "take down the Internet" I am sure Iran or China would have done it by now, but the vagueness of his last answer does add to the mystic of his image.
  • AlanDang
    Not really -- the black hats make money off the Internet -- it doesn't help them. By definition though, the risk is always about "taking down" a few IXP's or the +1 nodes.
  • Anonymous
    "Selectively granting privileges to enhanced functionality to Web sites is an area where most Web browsers can improve".

    They may not be core functions but everyone I know who is concerned with security on the Internet uses Firefow with the add-ins Noscript & Flashblock.
  • vaskodogama
    mrubermonkeyIf it were so easy to "take down the Internet" I am sure Iran or China would have done it by now, but the vagueness of his last answer does add to the mystic of his image.

    I am from Iran, All the Iranian Goverment can do, is blocking porn and politics web sites! :D
    [We People mostly not believe in the goverment, and ayatollahs, because they are mostly thieves! We Stand on the ground of wealth, and they are teroring us and eat our oil and money! This is a Tech site, so i'm not gonna talk more about this! cheers!]
  • pcworm
    I'm also from Iran , come one, we still connect using bloody dial up, you guys cant be serious! although due to the "no copyright" law we can buy Windows, Mathlab, VS 2008 team System,office 2007 and a lot more for less than a dollar each...:-) you dont need broadband here cause piracy is official
  • Gutbop
    Dino: I'm a die-hard Unix user and Mac OS X is the most convenient and functional Unix-based operating system that I have ever used. I can code in a traditional Unix environment, watch a DVD, and use Microsoft Office all on the same system. The system JUST WORKS and lets me get my job done.

    Ahahahaha. Really!? Are you kidding me? Did Apple pay you to say that?
  • Gutbop
    Dino: I'm a die-hard Unix user and Mac OS X is the most convenient and functional Unix-based operating system that I have ever used. I can code in a traditional Unix environment, watch a DVD, and use Microsoft Office all on the same system. The system JUST WORKS and lets me get my job done.

    Ahahahaha. Really!? Are you kidding me? Did Apple pay you to say that?
  • Gutbop
    Dino: I'm a die-hard Unix user and Mac OS X is the most convenient and functional Unix-based operating system that I have ever used. I can code in a traditional Unix environment, watch a DVD, and use Microsoft Office all on the same system. The system JUST WORKS and lets me get my job done.

    Ahahahaha. Really!? Are you kidding me? Did Apple pay you to say that?
  • Anonymous
    I am a Mac user as well. I also use many versions of Windows and Linux in VM. I am not a security expert or anything but why is everyone hung up on someone taking down the internet. Hackers use the net to make money or prove a point. I don't think they are going to shut the net down and hold it hostage, who would be forking over the money anyway. And if they did it to prove a point how would they ever get recognition for the task when all communication stops.
  • bounty
    Actually if there was a country that didn't like "the west," and they wanted to disrupt our economy, the internet is the softest target. I don't see North Korea flying over and dropping bombs on our factories. I could see them taking some DNS servers out and making it real hard for those factories to sell anything. And since info flows freely via the net, it's not like you need to use a ton of resources to gain this attack vector, just a few smart people, an internet connection and some time.
  • michaelahess
    DNS, the achilles heel of the net....I think I met this guy once, not sure, but a buddy of mine is in the exact same line of business, might have just heard him talking about him though.....the name just sounds so familiar, maybe he wiped my mind before we walked away.....{homer simpson} ummmm, conspiracy theories....
  • antiacid
    Honestly, I found this interview short, lacking in detail and depth and strong on the evangelism.

    Sure, you can make a point of saying "we aren't on Apple's payroll" but at the end of the article, it is still a pretty big advertisement to them for no reason. The main point is that the new malwares are not based on OS flaws but on browser flaws, yet you still go out of your way to advertise the security of OSX (even going as far as speculating on tiger leopard features).

    Anyway, if the guy obviously isn't going to comment or answer a question, cut it out of the interview instead of having a longer question than the associated answer...
  • AlanDang
    Browser flaws are still tied to the operating system. We bring it up because it's a natural question -- at the end of the day, there must be one computer that these security researchers are using and surprisingly, many security professionals use a Mac on a regular basis.

    By definition, I am a technology evangelist. I want to share with others the benefits of what technology can bring to the table and also what its limitations are. Fundamentally, I think that security is going to be as significant of an issue to a computer enthusiast as "cooling/thermal management" was. The threats are real and increasing. The people who claim that they have never been infected by malware are either ignorant that they have been infected or limiting their online experience by disabling flash, javascript, etc.

    Right and if we edited the comments, readers would start to cry censorship. That is the conversation we had.
  • zonezero
    I have worked for several ISP's and we never see a Mac that has anything other than hardware or configuration problems. I do see on a weekly basis people with Windows computers that are infected and some that are regularly infected with the malware of the week.

    I never owned or used a Mac other than those of my customers before my current job where I was forced to use a new iMac with 10.5 installed. While I still don't like the Mac and have more repect for those who use it.

    Computers are a tool and like any tool it can be used for the wrong job or improperly used for the right job. Pick the tool that best suits you and the job you are performing.
  • zonezero
    I have worked for several ISP's and we never see a Mac that has anything other than hardware or configuration problems. I do see on a weekly basis people with Windows computers that are infected and some that are regularly infected with the malware of the week.

    I never owned or used a Mac other than those of my customers before my current job where I was forced to use a new iMac with 10.5 installed. While I still don't like the Mac and have more repect for those who use it.

    Computers are a tool and like any tool it can be used for the wrong job or improperly used for the right job. Pick the tool that best suits you and the job you are performing.
  • zonezero
    I have worked for several ISP's and we never see a Mac that has anything other than hardware or configuration problems. I do see on a weekly basis people with Windows computers that are infected and some that are regularly infected with the malware of the week.

    I never owned or used a Mac other than those of my customers before my current job where I was forced to use a new iMac with 10.5 installed. While I still don't like the Mac and have more repect for those who use it.

    Computers are a tool and like any tool it can be used for the wrong job or improperly used for the right job. Pick the tool that best suits you and the job you are performing.
  • Anonymous
    He's cute. :P
  • dedhorse
    So basically, he uses OSX for web browsing, while all his real work is done on Vista in a VM, which tells you all you need to know about those two operating systems.
  • BillLake
    Wow, no matter what is said, people defend or attack the OS based on who made it. Apple or Microsoft are just tools, OS X is only less targeted while even if Vista is more secure it is more targeted. Currently you are safe on a OS X based PC and that is what he said. No one is saying it is more secure, in fact he said and so did Charlie Miller that OS X is less secure but safer.

    If you really want to be safe, why not use a diskless system, boot off a live CD and only use that to surf the web, then the infection can only be in the memory unless you get a virus that attacks the flash prom on the system.