The security researchers named the set of vulnerabilities "QuadRooter", attackers could use them to gain complete control of devices and unrestricted access to the data on them. Qualcomm was informed about the security flaws in April, they issued updates to OEMs but the problem is of course that most Android devices receive few, if any, updates.
What Android devices are at risk?Full details at CheckPoint.
QuadRooter vulnerabilities are found in software drivers that ship with Qualcomm chipsets. Any Android device built using these chipsets is at risk. The drivers, which control communication between chipset components, become incorporated into Android builds manufacturers develop for their devices.
Since the vulnerable drivers are pre-installed on devices at the point of manufacture, they can only be fixed by installing a patch from the distributor or carrier. Distributors and carriers issuing patches can only do so after receiving fixed driver packs from Qualcomm.
This situation highlights the inherent risks in the Android security model. Critical security updates must pass through the entire supply chain before they can be made available to end users. Once available, the end users must then be sure to install these updates to protect their devices and data.