Quadrooter was particularly troublesome because the set of four flaws (hence the name "quad") affected at least 900 million Android devices. These high-risk vulnerabilities would allow a dedicated and well-trained attacker to gain complete access to an affected phone and its data.
Google, which develops Android, said that most phones had received at least two or even three of the fixes in previous security bulletins. But the rest would remain outstanding for a month, until now, when the company released its regularly-scheduled monthly patches.
That didn't stop at least one phone maker pushing out a patch in the meanwhile.