InDesign Desktop versions ID18.5.2, ID19.3 and earlier are affected by a NULL Pointer Dereference vulnerability that could lead to an application denial-of-service (DoS). An attacker could exploit this vulnerability to crash the application, resulting in a denial of service condition. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.