Google has rolled out an over-the-air update to fix a serious security flaw with the Android operating system.

Some users of T-Mobile's G1 received a notification over the weekend that an update was available. This update fixed the Web browser vulnerability that could potentially enable a hacker to have access to information the WebKit browser may use.

Last week, security researchers from Independent Security Evaluators alerted the public to the flaw but did not release the exploit itself because the researchers wanted to give Google a chance to release a patch.

"A user of an Android phone who uses the Web browser to surf the Internet may be exploited if they visit a malicious page," the researchers wrote. "Upon visiting the malicious site, the attacker can run any code they wish with the privileges of the Web browser application."

Android is an open source operating system that uses more than 80 different open source packages. According to the researchers, the flaw stems from Google's not using the most up-to-date version of these packages.

"In other words, this particular security vulnerability that affects the G1 phone was known and fixed in the relevant software package, but Google used an older, still vulnerable version," ISE said.

The security firm did say that the impact of the exploit was somewhat limited because of Android's architecture. For example, an attacker could have access to things like cookies and saved passwords but would not be able to access other functions like the phone dialer.

Google said it takes security seriously and the update, which also includes other minor changes, should be rolled out to all G1 users shortly.