Examples include:

• GSM mobile phones have an identifier for the phone (separate from the identifier for the user) that can be blacklisted when the phone is stolen.
• Some car radios will stop working when the battery is disconnected, and only start working again when a numeric code is entered. This is intended to deter theft of the radio.
• In Windows Vista, Bitlocker can be used to encrypt files. One of the intended applications for this is that if someone steals your laptop, it will be difficult for them to gain access to your encrypted files.

Ross told a story of what happened when he needed to disconnect the battery on his car: the radio stopped working, and the code he had been given to reactivate it didn’t work - it was the wrong code.
Ross argues that these reactivation codes are unecessary, because other measures taken by the car manufacturers - such as making radios non-standard sizes, and hence not refittable in other car models - have made them redundant.

I described how the motherboard on a laptop had needed to be replaced recently. The motherboard contains the TPM chip, which contains the encryption keys needed to decrypt files protected with Bitlocker. If you replace the motherboard, the files on your hard disk will become unreadable, even if the disk is physically OK. Domain-joined Vista machines can be configured so that a sysadmin somewhere within your organization is able to recover the keys when this happens.

Both of these situations suffer from classic usability problems: the recovery procedures are invoked rarely (so users may not know what they’re supposed to do), and, if your system is configured incorrectly, you only find out when it is too late: you key in the code to your radio and it remains a doorstop; the admin you hoped was escrowing your keys turns out not to have the private key corresponding to the public key you were encrypting under (or, more subtly: the person with the authority to ask for your laptop’s key to be recovered is not you, because the appropriate admin has the wrong name for the laptop’s owner in their database).

I also described what happens when an XBox 360 is stolen. When you buy XBox downloadable content, you buy two licenses: one that’s valid on any XBox, as long as you’re logged in to XBox live; and one that’s valid on just your XBox, regardless of who’s logged in. If a burglar steals your Xbox, and you buy a new one, you need to get another license of the second type (for all the other people in your household who make use of it). The software makes this awkward, because it knows that you already have a license of the first type, and assumes that you couldn’t possibly want to buy it again. The work-around is to get a new email address, a new Microsoft Live Account, and a new Gamer Tag, and use these to repurchase the license. You can’t just change the gamertag, because XBox live doesn’t let the same Microsoft Live account have two gamertags. And yes, I know, your buddies in the MMORPG you were playing know you by your gamertag, so you don’t want to change it.

Fourth US airline to go Wi-Fi: Aircell says they have a fourth airline--after American, Delta, and Virgin America--on board for its in-flight Wi-Fi service. The aerial broadband provider's latest partner will be announced soon. Aircell's service went live in 15 American Airlines planes two weeks ago, and there's been a surprising lack of reporting from regular travelers or journalists since the big splash at the launch.

Microsoft, two universities research methods for better Wi-Fi handoff for vehicles: The researchers developed a method they call Vi-Fi, writes the Seattle Post-Intelligencer's Todd Bishop, which allows a system to maintain connections with several base stations at once, using a primary access point for traffic until a discontinuity is predicted or encountered. This allows seamless handoffs and continuous voice conversations.

Speaking of autos and Wi-Fi, concerns raised about Chrysler's in-car Wi-Fi option: Randall Stross wrote nearly two weeks ago in The New York Times about the problem of distraction. With the Internet at your fingertips, can you restrain yourself? The only problem with the humorous and accurate analysis is that millions of business travelers have 3G access via laptop cards already, so you'd think we'd already be seeing the bad effects of automotive area networks.

A Wi-Fi booster can't post availability signs on highway: The Nebraska town of Louisville has free Wi-Fi downtown, and wanted to post "Visitor Wi-Fi" on a highway sign as another amenity. The state highway department has a policy that doesn't allow the promotion of Wi-Fi, because they believe they'd be inundated. A resident who runs a local Internet firm installed his own signs on the highway; the roads department removed them; he remounted them; they were removed again. The idea of zoning and mounting a billboard apparently hasn't come to the city officials' minds (or perhaps they're prohibited).

The folks spreading misinformation about Wi-Fi health effects cause Ulster school to disable network: I can understand why non-technical folks might think that Wi-Fi has been proven to be unsafe, given the kind of information that's available on the Internet about wireless safety. While there are ongoing studies about the safety of cellular signals--and I'm convinced at this point there's no increased risk to an adult's health by using a cell phone--there is no specific and credible research linked to Wi-Fi, which broadcasts signals at a far lower level than a cell phone, most of the time in most uses.

Washington state shuts down rest-area Wi-Fi: The $3 for 15 minutes, $7 per day, or $30 per month Wi-Fi service at 28 of Washington's 42 rest areas has been turned off after a year for lack of use. Figures. The fees charged by Parsons and Road Connect aren't unreasonable for a nationally scoped plan, but are ridiculous for limited use. States should either bite the bullet and offer these service for free, partner with national roaming operators who can resell service into large networks of business travelers, or use ads to support the service. Highways in remote areas can typically pick up cell data networks, and ongoing costs should be minimal to operate such networks.

IEEE approves fast-roaming standard, 802.11r: This new standard is designed to improve the handoff of devices between base stations. This is accomplished in part by allowing base stations to communicate security and quality of service information so that a VoIP over WLAN phone can immediately reassociate without the delay of authentication and other handshaking.

Denver airport sees 7,000 connections on a single day last week due to Democratic National Convention: FreeFi released the usage figures recently to show how their service is operating. The network started with about 600 daily users when the switchover from fee to free happened 10 months ago, and now carries about 3,500 daily connections.

Coffee Bean & Tea Leaf goes free: The chain of about 700 cafes will have free Wi-Fi installed by now in all its company-owned stores (about 300).

For those of you who aren’t familiar with XSS Filter, a brief summary is that it is a client-side defense against reflected cross-site scripting (XSS) attacks.  It works by recognizing that reflected XSS attacks inject script into the string that the browser sends to the targeted web server.  If the server doesn’t neuter or strip out the injected script, it gets sent back to the browser and executed in the context of the target web page.  Bad things then happen.  At a high level, XSS Filter remembers the string that the browser sent to the server, and looks at the server’s response to see if any of the script was actually in that string.  If it was, then XSS Filter decides that it got there because it was injected by an XSS attack and blocks the script from executing.  The rest of the web page renders as usual.  This is a vastly oversimplified sketch of XSS Filter – for details, see the post by David Ross, inventor of XSS Filter on the Security Vulnerability Research and Defense blog.

So what does XSS Filter have to do with the SDL?  Well, for almost nine years, since XSS was first discovered at Microsoft, we’ve been trying to figure out effective ways to reduce vulnerability to XSS attacks.  Our focus has been on improving the ways that web page developers code their pages, and we’ve developed a lot of tools and techniques for making web content safer from XSS attacks and for detecting XSS vulnerabilities in live pages.  The SDL requires the use of many of these tools and techniques, and we’re sure we’ve prevented a lot of XSS vulnerabilities from being introduced into Microsoft web pages as a result. 

But while we identify (and the SDL requires) measures that allow developers to avoid classes of vulnerabilities, we also look to identify more sweeping solutions that can either 1) eliminate classes of vulnerabilities, 2) reduce their severity, or 3) reduce the likelihood of attacks being successful.  The process usually starts from deep understanding of a class of vulnerabilities and attacks, and then we broaden defenses from there.  In the case of XSS Filter, David’s years of work researching XSS led him to come up with an approach that blocks many of the most common vulnerabilities to reflected attacks found on the web today.  The solution is compatible with existing web pages (doesn’t “break the web”) and thus we were able to enable it by default for users of Internet Explorer 8.  Because it’s a client-side mitigation, it will help protect users from attacks even though the sites they visit may be vulnerable to XSS. 

Our work on buffer overrun defenses follows a somewhat similar pattern – we started by prescribing coding techniques, banning the use of some APIs, and building tools that detect coding constructs that look like buffer overruns.  As we gained a deeper understanding of how buffer overruns can be exploited, we enhanced the /GS compiler flag and added ASLR in a quest to cause classes of exploits to fail even if a buffer overrun remains.  We’re not yet close to eliminating the SDL requirements for use of tools and coding techniques, but the SDL also requires the use of the mitigations to reduce the severity of vulnerabilities that slip past.  Will we ever get to the point where the mitigating technologies are so strong that we can relax the coding requirements?  Maybe not, but we will continue to introduce technologies that reduce the chances of a successful attack.

Similarly, in the case of XSS, even after IE8 ships, the SDL will continue to require the use of safe web site coding practices and tools such as the Anti-XSS library both to protect users of browsers other than IE8 and to provide protection in recognition of the fact that XSS Filter is a mitigation or defense in depth rather than a complete solution.  But we’ll also be keeping our eyes open (and doing active research) in the quest for an even more effective defense – whether client or server side – that eliminates XSS for good.

This post is a little far afield from the normal content of the SDL blog, but I thought it was important to provide a picture of the role of security science and security research in defining SDL requirements and in making major improvements in software security.  You can read more about our work in security science in the Security Vulnerability Research and Defense blog.

Synopsis:  Blue Box #81: iSkoot vulnerability, OFCOM legislation, VoIP security news and more

Welcome to Blue Box: The VoIP Security Podcast #81, a 42-minute podcast  from Dan York and Jonathan Zar covering VoIP security news, comments and opinions.   

Download the show here (MP3, 19MB) or subscribe to the RSS feed to download the show automatically. 

NOTE: This show was originally recorded on May 21, 2008.

You may also listen to this podcast right now:

Show Content:

• 00:20 - Intro to the show, contact information and how to provide comments.  Welcome to all the new listeners - and to all those listeners who have been here for so long!
• Programming notes:
  • Note about the hiatus
• Voice of VOIPSA: Are your Skype username and password completely exposed if you use iSkoot?
• Voice of VOIPSA: Chronology
• Voice of VOIPSA: iSkoot disclosure of Skype credentials resolved – new version by Wednesday
• Ofcom confirms VoIP providers must provide access to 999 and 112 – and Hannes Tschofenig points to 4th Emergency Services Coordination Workshop and presentation about the UK
• MarketingVOX: British Proposal May Force ISPs to Fork Over Online Activity, Emails, VOIP Calls pointing to Reuters article: Britain mulls plan to store all email and calls
• Enterprise VoIP Planet: VoIP Security: SIP-Versatile but Vulnerable


• IT Business Edge: Pay Attention to VoIP Security Before The Storm
• NetworkWorld: Business Guide to VoIP Security


• Pocket-lint: Fraudsters targeting VoIP Users based on report out of Newport Networks (reported in VoIP News) – also covered at Fierce VoIP: Newport Networks riles up VoIP Security Fears and Computeractive: Phreak-out over VoIP and TechHerald article


• Network World: Security and management considerations when deploying OCS


• LXer: Secure Calling Initiative Reaches Second Milestone pointing to Secure Calling Initiative



• [H]Enthusiast: Mobile Phones, VoIP Not Secure, Experts Warn=



• VoIP News: The Essential Guide to VoIP Privacy



• Voice of VOIPSA: Information Week interviews SecureLogix about VoIP security


• eWeek: VoIP Security through Responsible Software Development


• Microsoft gives back door keys to Vista to police


• Comment (blog) from Martyn Davies


• Comment (email) from Detlef


• Comment (email) from Dan McGinn-Combs


• Review of the last week's traffic on the VOIPSEC public mailing list 


• Wrap-up of the show


• 41:43 - End of show 

Comments, suggestions and feedback are welcome either as replies to this post  or via e-mail to blueboxpodcast@gmail.com.  Audio comments sent as attached MP3 files are definitely welcome and will be played in future shows.  You may also call the listener comment line at either +1-415-830-5439 or via SIP to 'bluebox@voipuser.org' to leave a comment there. 

Thank you for listening and please do let us know what you think of the show.

Synopsis:  Blue Box #80: VoIPShield vulnerabilities, what is ethical disclosure?, SIP trunking, VoIP security news, new nomadism, and much more...

Welcome to Blue Box: The VoIP Security Podcast #80, a 44-minute podcast  from Dan York and Jonathan Zar covering VoIP security news, comments and opinions.   

Download the show here (MP3, 19MB) or subscribe to the RSS feed to download the show automatically. 

NOTE: This show was originally recorded on April 21, 2008.

You may also listen to this podcast right now:

Show Content:

• 00:20 - Intro to the show, contact information and how to provide comments.  Welcome to all the new listeners - and to all those listeners who have been here for so long!
• Programming notes:
  • Note about the hiatus
• Voice of VOIPSA: Are your Skype username and password completely exposed if you use iSkoot?
• Voice of VOIPSA: Chronology
• Voice of VOIPSA: iSkoot disclosure of Skype credentials resolved – new version by Wednesday
• Ofcom confirms VoIP providers must provide access to 999 and 112 – and Hannes Tschofenig points to 4th Emergency Services Coordination Workshop and presentation about the UK
• MarketingVOX: British Proposal May Force ISPs to Fork Over Online Activity, Emails, VOIP Calls pointing to Reuters article: Britain mulls plan to store all email and calls
• Enterprise VoIP Planet: VoIP Security: SIP-Versatile but Vulnerable


• IT Business Edge: Pay Attention to VoIP Security Before The Storm
• NetworkWorld: Business Guide to VoIP Security


• Pocket-lint: Fraudsters targeting VoIP Users based on report out of Newport Networks (reported in VoIP News) – also covered at Fierce VoIP: Newport Networks riles up VoIP Security Fears and Computeractive: Phreak-out over VoIP and TechHerald article


• Network World: Security and management considerations when deploying OCS


• LXer: Secure Calling Initiative Reaches Second Milestone pointing to Secure Calling Initiative



• [H]Enthusiast: Mobile Phones, VoIP Not Secure, Experts Warn=



• VoIP News: The Essential Guide to VoIP Privacy



• Voice of VOIPSA: Information Week interviews SecureLogix about VoIP security


• eWeek: VoIP Security through Responsible Software Development


• Microsoft gives back door keys to Vista to police


• Comment (blog) from Martyn Davies


• Comment (email) from Detlef


• Comment (email) from Dan McGinn-Combs


• Review of the last week's traffic on the VOIPSEC public mailing list 


• Wrap-up of the show


• 41:43 - End of show 

Comments, suggestions and feedback are welcome either as replies to this post  or via e-mail to blueboxpodcast@gmail.com.  Audio comments sent as attached MP3 files are definitely welcome and will be played in future shows.  You may also call the listener comment line at either +1-415-830-5439 or via SIP to 'bluebox@voipuser.org' to leave a comment there. 

Thank you for listening and please do let us know what you think of the show.