InDesign Desktop versions ID19.5.2, ID20.2 and earlier are affected by a NULL Pointer Dereference vulnerability that could lead to application denial-of-service. An attacker could exploit this vulnerability to crash the application, causing disruption in service. 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.