Security Experts:

Metasploit Module Released for New UXSS Vulnerability in Android Browser

A universal cross-site scripting (UXSS) vulnerability has been identified in the Android browser that’s installed by default on many Android smartphones, researchers reported on Thursday.

The flaw was identified and reported to Google by Pakistani security researcher Rafay Baloch. The expert coordinated the disclosure of the bug with the security firm Rapid7, which released a Metasploit module for it.

The vulnerability, which affects the WebView component, occurs "when replacing the 'data' attribute of a given HTML object with a JavaScript URL scheme," explained Tod Beardsley, technical lead for the Metasploit framework.

An attacker can leverage the UXSS flaw to scrape cookie data and page contents from a vulnerable browser window, Rapid7 said. The company has noted that target URLs using X-Frame-Options are not affected.

The security hole can be exploited on all versions of the Android Open Source Platform (AOSP) browser, shipped by default with all versions of the Android operating system prior to 4.4 (KitKat). Android applications incorporating versions of WebView prior to 4.4 are also impacted, Beardsley said.

Google released the Android platform version numbers for November a few days ago, and the report shows that close to 70% of Android smartphones use pre-KitKat versions of the operating system.

While Google published a fix for this bug on September 30, most Android users will probably not get it because of the way the Android ecosystem works -- unless they buy a new phone.

"For many, many people, buying a new phone just isn't practical; the people who are most likely affected by 'legacy' Android bugs are the same people who couldn't afford a fancy 'latest' Android handset in the first place," Beardsley said in a blog post. "In other words, it looks like a billion phones aren't going to see this patch any time soon, if ever. It's nice that the patch exists, but Google doesn't seem to have any practical way of getting it out to the world."

The impact of this vulnerability is similar to a couple of other Android browser bugs identified by Baloch in recent months. The researcher reported identifying a Same Origin Policy (SOP) bypass flaw (CVE-2014-6041) in September, and another one in October. The second issue uncovered by Baloch had been fixed by Google in the Chrome Webkit three years ago.

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.