I was only reading about this a few days ago, and it would appear that if your smartphone is android based, and has a qualcomm chipset then several vulnerabilities allow remote compromise over the air.
The vulnerabilities in question are:
CVE-2019-10539 (Compromising WLAN) — The first flaw is a buffer overflow issue that resides in the Qualcomm WLAN firmware due to lack of length check when parsing the extended cap IE header length.
CVE-2019-10540 (WLAN into Modem issue) — The second issue is also a buffer-overflow flaw that also resides in the Qualcomm WLAN firmware and affects its neighborhood area network (NAN) function due to lack of check of count value received in NAN availability attribute.
CVE-2019-10538 (Modem into Linux Kernel issue) — The third issue lies in Qualcomm's Linux kernel driver for Android that can be exploited by subsequently sending malicious inputs from the Wi-Fi chipset to overwrite parts of Linux kernel running the device's main Android operating system.
Once compromised, the kernel gives attackers full system access, including the ability to install rootkits, extract sensitive information, and perform other malicious actions, all while evading detection.