Unified Automation UaGateway OPC UA Server Use-After-Free Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Unified Automation UaGateway. Authentication is required to exploit this vulnerability. The specific flaw exists within the implementation of the ImportXML function. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20497.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.