A vulnerability classified as critical was found in Linux Kernel up to 5.14.14. Affected by this vulnerability is the function
cmtp_add_connection
of the file drivers/isdn/capi/kcapi.c of the component isdn. The manipulation leads to improper validation of array index.
This vulnerability is known as CVE-2021-4439. The attack needs to be initiated within the local network. There is no exploit available.
It is recommended to upgrade the affected component.