MikroTik RouterOS 6.40.5, the SMB service contains a memory corruption vulnerability. Remote, unauthenticated attackers can exploit this issue by sending specially crafted packets, triggering a null pointer dereference. This leads to a Remote Denial of Service (DoS), rendering the SMB service unavailable.
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.