According to the information, the issues are already fixed. The vulnerabilities were exploited by an Android application that tricked some users into installing them without using the Google App Store.
The first vulnerability in this chain (CVE-2021-25337) is the arbitrary file read and write, which was the foundation of this chain, used four different times, and used at least once in each step.
The second vulnerability (CVE-2021-25369) used by the chain is an information leak to leak the address of the task_struct and sys_call_table. Meanwhile, the final vulnerability in the chain (CVE-2021-25370) is a use-after-free of a file struct in the Display and Enhancement Controller (DECON) Samsung driver for the Display Processing Unit (DPU).
Furthermore, Google reported these vulnerabilities to Samsung in late 2020, when it received samples of the exploit. Whereas, the Korean company released the patch in March 2021.