Security experts are praising the improvements in the latest version of Firefox, which fixes a total of 14 vulnerabilities, five critical, and adds three security-related features.
Running scripts found on web pages in sandboxes is a trend among makers of browsers. The special containers limit applications to accessing only the services they need.
The Firefox patch is important because hackers have been focusing on finding holes in sandboxes, Wolfgang Kandek, chief technology officer of Qualys, said. "People are testing their boundaries and how they can escape those boundaries," he said.
Another critical patch fixes a flaw that would allow a hacker to bypass the browsers same-compartment security wrappers, or SCSW. The feature prevents a web page from executing code outside of the page's context.
Restraints placed on code execution in a browser, or operating system, is favored by security experts. "It's a preventive measure rather than a reactive one," Kandek said.
The other three critical patches fix vulnerabilities related to data leakage, memory corruption and "miscellaneous memory safety hazards." Along with the five critical fixes, Mozilla released four patches with a high priority, and listed five as moderate.
None of the vulnerabilities had been exploited in the wild, and all are fixed through Firefox's automatic update feature, which pushes out patches without the user getting involved. However, businesses can bypass the feature and deploy patches manually.
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The latest patches did not reflect any lapse in security on the part of Mozilla, Marcus Carey, security researcher for Rapid7, said. "The vulnerabilities they patched are definitely serious, but I don't see anything that jumps out at me," he said. "There's nothing in the wild right now that I'm aware of."
Overall, Mozilla has stayed on top of security, Kandek said. "They're doing great work in the security area."
The latest Firefox also boosts privacy by enabling HTTPS when making web searches via Google. The feature prevents anyone but Google from seeing search queries. Normally, such queries could be seen by network administrators when a person is on a corporate network, or by a service provider or any other entity monitoring traffic on a public or shared Wi-Fi.
"For people who are adamant about Internet privacy, it's going make them happy," Marcus said.
Google is the only search engine that provides the necessary technology for the new feature, according to Mozilla. The company plans to add other search engines in the future when possible.
Mozilla is also giving Firefox users more information about the security of the Web sites they visit. Icons added to the URL bar include a grey globe for non-HTTPS sites, a grey lock icon for HTTPS sites and a green lock icon for sites that use HTTPS and an extended validation certificate. The name of the certificate's owner will also be displayed.
The remaining security feature blocks the automatic display of plug-in-based content, such as Flash videos, Java applets and PDF files. The so-called click-to-play feature requires the Firefox user to click on a static image before the content is loaded into the plug-in.
Such precautions are meant to give users a chance to consider whether the content offered is legitimate or malicious. Similar features have been available in Google Chrome and Opera.
The effectiveness of the security measure depends on users being savvy enough to tell when content offered on a Web page doesn't seem right. Studies show that most people click to load content without much thought.
The Firefox implementation of click-to-play is not yet completed and can only be started manually by typing "about:config" in the URL bar.