Facepalm

facepalm
There’s been a lot of attention around the Israeli facial recognition startup Face.com.  They, amongst other things, make a mobile app called “KLIK” which lets users tag their friend’s faces in real-time, as they walk down the street. Just today, they announced that they’re being acquired by Facebook for $100M.

A few weeks ago, I noticed a different kind of excitement surrounding the startup. I found an extremely basic vulnerability in the which the app allows access to other user’s KLIK information, including private ‘authentication tokens’ (i.e keys) for user’s Facebook & Twitter accounts (KLIK relies on Facebook to use the app).

Face.com essentially allowed anyone to hijack a KLIK user’s Facebook and Twitter accounts to get access to photos and social graph (which enables ‘face prints’), even if that information isn’t public.

[Read more...]

Cookies from Nowhere

gingerbread_man

Google is tracking Safari users across the web even though when they attempt to block 3rd party cookies and have never visited Google.com. This is a function of the anti phishing and malware lists used by both Safari, Firefox (and, of course, Chrome) that automatically update from Google in the background and places Google cookies.

This is a separate issue than the one uncovered Feb 17, 2012 surrounding Google circumvention of Safari’s default cookie blocking features. Essentially, even though Google has fixed the Doubleclick issue due to ‘social sync’, they are still able to track Safari users everywhere there is a +1 button on the web, even when users have 3rd party cookies blocked.

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Analysis of Carrier IQ Software

Log Pile by Lars Hammer on Flickr http://flic.kr/p/a4XR3b

Log Pile by Lars Hammer on Flickr http://flic.kr/p/a4XR3b

There has been some confusion and multiple conflicting statements about the Carrier IQ issues that were highlighted in Trevor Ekharts’s initial video some weeks ago.  I will attempt to hopefully clarify some of that confusion and show that, despite statements to the contrary, there is capture and transmission of sensitive information to 3rd parties resulting from misconfigured Carrier IQ software. [Read more...]

Flash Cookies and Privacy II

A detailed technical followup to Flash Cookies and Privacy II, describing the mechanisms behind Hulu/KISSmetrics’ respawning practices

cookiemonsterdeleteI thought I’d take the time to elaborate a bit further regarding the technical mechanisms described in our Flash Cookies and Privacy II paper that generated a bit of buzz recently. For a bit of background, I, along with Chris Hoofnagle and Nathan Good, had the honor of supervising Mika Ayenson and Dietrich J. Wambach in replicating our previous 2009 study which found that websites were circumventing user choice by deliberately restoring previously deleted HTTP cookies using persistent storage outside of the control of the browser (a practice we dubbed ‘respawning’).

In our follow up study, we found that Hulu was still respawning deleted user cookies using homegrown Flash and Javascript code present on the Hulu.com site. Additionally, Hulu, Spotify, and many others were also respawning using code provided by analytics firm KISSmetrics.* Hitten Shah, the founder of KISSmetrics, initially confirmed that the research surrounding respawning was correct in an interview with Ryan Singel although he later criticized the findings after a lawsuit was filed.

(*Hulu and KISSmetrics have both ceased respawning as of July 29th 2011)

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Flash Cookies and Privacy II: Now with HTML5 and ETag Respawning

KISSmetricspersistentracking_large

In August 2009, the research team published Flash Cookies and Privacy, a paper that demonstrated that popular websites were using Flash cookies to track users.  Some advertisers has adopted this technology because it allowed persistent tracking, even where users had taken steps to avoid web profiling. This allowed sites to reinstantiate HTTP cookies deleted by a user, making tracking more resistant to users’ privacy-setting behaviors.

In this followup study, we reassess the flash cookies landscape and examine a new tracking vector, HTML5 local storage and cache cookies via eTags. [Read more...]

Flash Cookies and Privacy

flashcookies1.fig3

In August 2009, I and other graduate students at the University of California, Berkeley – School of Law, Berkeley Center for Law & Technology published Flash Cookies and Privacy, a paper that examined of the use of ‘Flash cookies’ by popular websites.

Websites and Cookies

Advertisers are increasingly concerned about unique tracking of users online. Several studies have found that over 30% of users delete first party HTTP cookies once a month, thus leading to overestimation of the number of true unique visitors to websites, and attendant overpayment for advertising impressions.

Mindful of this problem, online advertising companies have attempted to increase the reliability of tracking methods. In 2005, United Virtualities (UV), an online advertising company, exclaimed, “All advertisers, websites and networks use [HTTP] cookies for targeted advertising, but cookies are under attack.” The company announced that it had, “developed a backup ID system for cookies set by web sites, ad networks and advertisers, but increasingly deleted by users. UV’s ‘Persistent Identification Element’ (PIE) is tagged to the user’s browser, providing each with a unique ID just like traditional cookie coding. However, PIEs cannot be deleted by any commercially available antispyware, mal-ware, or adware removal program. They will even function at the default security setting for Internet Explorer.”

United Virtualities’ PIE leveraged a feature in Adobe’s Flash MX: the “local shared object,” also known as the “Flash cookie.” [Read more...]