While Google said in a blog post on April 9 that all versions of Android are immune to the flaw, it added that the “limited exception” was one version dubbed 4.1.1, which was released in 2012.
Security researchers said that version of Android is still used in millions of smartphones and tablets, including popular models made by Samsung Electronics Co., HTC Corp. and other manufacturers. Google statistics show that 34 percent of Android devices use variations of the 4.1 software. The company said less than 10 percent of active devices are vulnerable. More than 900 million Android devices have been activated worldwide.