Thursday, March 31, 2011

Chrome warns users of out-of-date browser plugins

The new version of Google Chrome is not only speedier and simpler but it also improves user security by automatically disabling out-of-date, vulnerable browser plugins.

As browsers get better at auto-updating, out-of-date plugins are becoming the weakest link against malware attacks. Thousands of web sites are compromised every week, turning those sites into malware distribution vectors by actively exploiting out-of-date plugins that run in the browser. Simply visiting one of these sites is usually enough to get your computer infected.

Keeping all of your plugins up-to-date with the latest security fixes can be a hassle, so a while ago we started using our 20% time to develop a solution. The initial implementation was a Chrome extension called “SecBrowsing,” which kept track of the latest plugin versions and encouraged users to update accordingly. The extension helped us gather valuable knowledge about plugins, and we started working with the Chrome team to build the feature right inside the browser.

With the latest version of Chrome, users will be automatically warned about any out-of-date plugins. If you run into a page that requires a plugin that’s not current, it won’t run by default. Instead, you’ll see a message that will help you get the latest, most secure version of the plugin. An example of this message is below, and you can read more about the feature at the Chromium blog.

Friday, March 11, 2011

MHTML vulnerability under active exploitation

We’ve noticed some highly targeted and apparently politically motivated attacks against our users. We believe activists may have been a specific target. We’ve also seen attacks against users of another popular social site. All these attacks abuse a publicly-disclosed MHTML vulnerability for which an exploit was publicly posted in January 2011. Users browsing with the Internet Explorer browser are affected.

For now, we recommend concerned users and corporations seriously consider deploying Microsoft’s temporary Fixit to block this attack until an official patch is available.

To help protect users of our services, we have deployed various server-side defenses to make the MHTML vulnerability harder to exploit. That said, these are not tenable long-term solutions, and we can’t guarantee them to be 100% reliable or comprehensive. We’re working with Microsoft to develop a comprehensive solution for this issue.

The abuse of this vulnerability is also interesting because it represents a new quality in the exploitation of web-level vulnerabilities. To date, similar attacks focused on directly compromising users' systems, as opposed to leveraging vulnerabilities to interact with web