Wednesday, July 16, 2008

Are you using the latest web browser?

In view of mass defacements of hundreds of thousand of web pages - with the intent to misuse them to launch drive-by download attacks - security researchers from ETH Zurich, Google, and IBM Internet Security Systems were interested in looking at the other side of the attack: the web browser. By analyzing the web browser versions seen in visits to Google websites, they have shown that more than 600 million Internet users don't use the latest version of their browser.

Slow migration to latest browser version
The researchers' paper, entitled "Understanding the Web Browser Threat", shows that as of June 2008, only 59.1% percent of Internet users worldwide use the latest major version of their preferred web browser. Firefox users are the most attentive: 92.2% of them surfed with Firefox 2, the latest major version before the recently released 3.0. Only 52.5% of Microsoft Internet Explorer users have updated to version 7, which is the most secure according to multiple publicly-cited Microsoft experts (among them Sandi Hardmeier). The study revealed that 637 million Internet users worldwide who use web browsers are either not running the latest version of their preferred browser or have not installed the latest patches. These users are vulnerable to exploitation due to their web browser's "built-in" vulnerabilities and the lack of more recent security mechanisms such as improved phishing protection.

Neglected security patches
Over the past 18 months, the study also shows, a maximum of 83.3% of Firefox users were using the latest major version of the web browser and also had all current patches installed (i.e. latest minor version). Only 56.1% and 47.6% of Opera and Internet Explorer users, respectively, were similarly utilizing fully-patched web browsers. Apple users are no better: since the public release of Safari 3, only 65.3% of users operate the latest Safari version.

Maximum measured share of users surfing the web with the most secure versions of Firefox, Safari, Opera and Internet Explorer in June 2008 as seen on Google websites.

Obsolete browser warning
The study's most important finding is that technical measures now in place do not sufficiently guarantee browser security, and that users' security awareness must be further developed. The problem is that most users are unaware that they are not using their browser's latest version. It must be made clear to web browser users that outdated software is associated with significantly higher risk. The researchers therefore suggest that, as a critical component of web software, a visible warning be instituted that warns the user of missing security patches in a way analogous to the 'best before' date in the perishable food industry. Software updates must also be made easier to find. The resulting transparency would go far in contributing to end user awareness of software weaknesses, and allow users to better evaluate risks.

Example "best before" implementation on a Web browser

As a side effect, having users migrate faster to the latest browser version would not only increase security but also make the lives of webmasters easier, as they would need to test and optimize websites for fewer older versions of web browsers.

Tuesday, July 1, 2008

Meet ratproxy, our passive web security assessment tool

We're happy to announce that we've just open-sourced ratproxy, a passive web application security assessment tool that we've been using internally at Google. This utility, developed by our information security engineering team, is designed to transparently analyze legitimate, browser-driven interactions with a tested web property and automatically pinpoint, annotate, and prioritize potential flaws or areas of concern.

The proxy analyzes problems such as cross-site script inclusion threats, insufficient cross-site request forgery defenses, caching issues, cross-site scripting candidates, potentially unsafe cross-domain code inclusion schemes and information leakage scenarios, and much more. (A more-detailed discussion of these features and information on securing vulnerable applications is provided here.) Compared with more-traditional active crawlers, or with fully manual request inspection and modification frameworks, this approach offers several significant advantages in terms of minimized overhead; marginalized risk of site disruptions; high coverage of complex, client-driven application states in web 2.0 solutions; and insight into dynamic cross-domain trust models.

We decided to make this tool freely available as open source because we feel it will be a valuable contribution to the information security community, helping advance the community's understanding of security challenges associated with contemporary web technologies. We believe that responsible security research brings a net overall benefit to the safety of the Web as a whole, and have released this tool explicitly to support that kind of research.

To download the proxy, please visit this page. Also, please keep in mind that the proxy is designed solely to highlight interesting patterns in web applications, and a further analysis by a security professional is often required to interpret the results and their significance for the tested platform.