The ThreadX-based firmware on Marvell Avastar Wi-Fi devices, models 88W8787, 88W8797, 88W8801, 88W8897, and 88W8997, allows remote attackers to execute arbitrary code or cause a denial of service (block pool overflow) via malformed Wi-Fi packets during identification of available Wi-Fi networks. Exploitation of the Wi-Fi device can lead to exploitation of the host application processor in some cases, but this depends on several factors including host OS hardening and the availability of DMA.
https://www.synology.com/security/advisory/Synology_SA_19_07
https://www.scribd.com/document/398350818/WiFi-CVE-2019-6496-Marvell-s-Statement