Vulnerabilities / Threats
8/9/2010
12:50 PM
50%
50%

Web Browser Privacy Settings Flawed

Private and anonymous settings in Firefox, Internet Explorer, and others can expose more details than users expect, security researchers find.

Do you believe that your browser's privacy settings hide your viewing habits? Think again.

According to researchers from Stanford University and Carnegie Mellon, their first-ever study of the privacy mode in browsers found multiple weaknesses, which attackers could exploit to reconstruct a browser's true history. The researchers plan to present their findings at this week's Usenix Security Symposium in Washington.

To assess the security of browsers' privacy modes, the researchers examined privacy controls, cookie controls, and object controls in Firefox 3.5, Internet Explorer 8, Google Chrome, Apple Safari 4, and Opera 10. They also evaluated numerous add-ons, including CookieSafe for cookie controls in Firefox, AdBlock Plus for controlling objects -- such as suppressing banner advertisements from displaying -- in Firefox, and PithHelmet for Safari object control.

What the researchers found were numerous vulnerabilities in how these browsers and add-ons approach privacy. As a result, "current private browsing implementations provide privacy against some local and web attackers, but can be defeated by determined attackers," they said.

For example, browsers sometimes leak information when in private mode. For starters, any Certificate Authority (CA) certificates cached when a user is in private mode persist when they switch out of private mode. "This is significant privacy violation," according to the researchers.

In addition, half of the Firefox JavaScript plug-ins they studied, and 71 out of the top 100 Safari plug-ins, store their data to disk, which means that an enterprising attacker could later reconstruct which sites had been visited.

When it comes to browser privacy, or lack thereof, the researchers also cautioned that more flaws and vulnerabilities could exist, such as accessing browsing data that's been cached in memory.

In short, "privacy" mode can be anything but, at least against a determined adversary or forensic investigator.

Then again, what draws people to use privacy mode? To find out, the researchers also spent $120 to purchase 155,216 impressions for two advertising campaigns they created, running simultaneously online, then used code in the advertisements to detect whether someone was in private browsing mode. "We found that private browsing was more popular at adult web sites than at gift shopping sites and news sites, which shared a roughly equal level of private browsing use," according to their study.

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Dark Reading December Tech Digest
Experts weigh in on the pros and cons of end-user security training.
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2010-5312
Published: 2014-11-24
Cross-site scripting (XSS) vulnerability in jquery.ui.dialog.js in the Dialog widget in jQuery UI before 1.10.0 allows remote attackers to inject arbitrary web script or HTML via the title option.

CVE-2012-6662
Published: 2014-11-24
Cross-site scripting (XSS) vulnerability in the default content option in jquery.ui.tooltip.js in the Tooltip widget in jQuery UI before 1.10.0 allows remote attackers to inject arbitrary web script or HTML via the title attribute, which is not properly handled in the autocomplete combo box demo.

CVE-2014-1424
Published: 2014-11-24
apparmor_parser in the apparmor package before 2.8.95~2430-0ubuntu5.1 in Ubuntu 14.04 allows attackers to bypass AppArmor policies via unspecified vectors, related to a "miscompilation flaw."

CVE-2014-7817
Published: 2014-11-24
The wordexp function in GNU C Library (aka glibc) 2.21 does not enforce the WRDE_NOCMD flag, which allows context-dependent attackers to execute arbitrary commands, as demonstrated by input containing "$((`...`))".

CVE-2014-7821
Published: 2014-11-24
OpenStack Neutron before 2014.1.4 and 2014.2.x before 2014.2.1 allows remote authenticated users to cause a denial of service (crash) via a crafted dns_nameservers value in the DNS configuration.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
Now that the holiday season is about to begin both online and in stores, will this be yet another season of nonstop gifting to cybercriminals?